<?xml version="1.0" encoding="UTF-8"?><rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:content="http://purl.org/rss/1.0/modules/content/" xmlns:atom="http://www.w3.org/2005/Atom" version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd" xmlns:googleplay="http://www.google.com/schemas/play-podcasts/1.0"><channel><title><![CDATA[Data S2: API]]></title><description><![CDATA[This section documents experimental APIs and systems developed as part of ongoing research. These artifacts are exploratory by design and exist to support learning, analysis, and discussion.]]></description><link>https://www.datas2.com/s/api</link><image><url>https://substackcdn.com/image/fetch/$s_!dacp!,w_256,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff85e539c-200d-4cfd-9d75-2f8c24b44c79_300x300.png</url><title>Data S2: API</title><link>https://www.datas2.com/s/api</link></image><generator>Substack</generator><lastBuildDate>Sat, 11 Apr 2026 03:50:04 GMT</lastBuildDate><atom:link href="https://www.datas2.com/feed" rel="self" type="application/rss+xml"/><copyright><![CDATA[Augusto Machado]]></copyright><language><![CDATA[en]]></language><webMaster><![CDATA[datas2@substack.com]]></webMaster><itunes:owner><itunes:email><![CDATA[datas2@substack.com]]></itunes:email><itunes:name><![CDATA[Augusto Machado]]></itunes:name></itunes:owner><itunes:author><![CDATA[Augusto Machado]]></itunes:author><googleplay:owner><![CDATA[datas2@substack.com]]></googleplay:owner><googleplay:email><![CDATA[datas2@substack.com]]></googleplay:email><googleplay:author><![CDATA[Augusto Machado]]></googleplay:author><itunes:block><![CDATA[Yes]]></itunes:block><item><title><![CDATA[Noctua API: Minimum Context Signals for Real-Time Fraud Suspicion]]></title><description><![CDATA[How much can responsibly be known about a transaction before money moves? In real-time financial systems, this question is no longer theoretical.]]></description><link>https://www.datas2.com/p/noctua-api-small-data-for-real-time</link><guid isPermaLink="false">https://www.datas2.com/p/noctua-api-small-data-for-real-time</guid><dc:creator><![CDATA[Augusto Machado]]></dc:creator><pubDate>Mon, 02 Mar 2026 21:51:27 GMT</pubDate><enclosure url="https://substackcdn.com/image/fetch/$s_!bDeK!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png" length="0" type="image/jpeg"/><content:encoded><![CDATA[<div class="captioned-image-container"><figure><a class="image-link image2 is-viewable-img" target="_blank" href="https://substackcdn.com/image/fetch/$s_!bDeK!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png" data-component-name="Image2ToDOM"><div class="image2-inset"><picture><source type="image/webp" srcset="https://substackcdn.com/image/fetch/$s_!bDeK!,w_424,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 424w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_848,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 848w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_1272,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 1272w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 1456w" sizes="100vw"><img src="https://substackcdn.com/image/fetch/$s_!bDeK!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png" width="1280" height="894" data-attrs="{&quot;src&quot;:&quot;https://substack-post-media.s3.amazonaws.com/public/images/f6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png&quot;,&quot;srcNoWatermark&quot;:null,&quot;fullscreen&quot;:null,&quot;imageSize&quot;:null,&quot;height&quot;:894,&quot;width&quot;:1280,&quot;resizeWidth&quot;:null,&quot;bytes&quot;:2119004,&quot;alt&quot;:null,&quot;title&quot;:null,&quot;type&quot;:&quot;image/png&quot;,&quot;href&quot;:null,&quot;belowTheFold&quot;:false,&quot;topImage&quot;:true,&quot;internalRedirect&quot;:&quot;https://www.datas2.com/i/188566665?img=https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png&quot;,&quot;isProcessing&quot;:false,&quot;align&quot;:null,&quot;offset&quot;:false}" class="sizing-normal" alt="" srcset="https://substackcdn.com/image/fetch/$s_!bDeK!,w_424,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 424w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_848,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 848w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_1272,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 1272w, https://substackcdn.com/image/fetch/$s_!bDeK!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff6848f18-dcf0-42aa-8a6c-586f0a00b4d4_1280x894.png 1456w" sizes="100vw" fetchpriority="high"></picture><div class="image-link-expand"><div class="pencraft pc-display-flex pc-gap-8 pc-reset"><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container restack-image"><svg role="img" width="20" height="20" viewBox="0 0 20 20" fill="none" stroke-width="1.5" stroke="var(--color-fg-primary)" stroke-linecap="round" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg"><g><title></title><path d="M2.53001 7.81595C3.49179 4.73911 6.43281 2.5 9.91173 2.5C13.1684 2.5 15.9537 4.46214 17.0852 7.23684L17.6179 8.67647M17.6179 8.67647L18.5002 4.26471M17.6179 8.67647L13.6473 6.91176M17.4995 12.1841C16.5378 15.2609 13.5967 17.5 10.1178 17.5C6.86118 17.5 4.07589 15.5379 2.94432 12.7632L2.41165 11.3235M2.41165 11.3235L1.5293 15.7353M2.41165 11.3235L6.38224 13.0882"></path></g></svg></button><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container view-image"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-maximize2 lucide-maximize-2"><polyline points="15 3 21 3 21 9"></polyline><polyline points="9 21 3 21 3 15"></polyline><line x1="21" x2="14" y1="3" y2="10"></line><line x1="3" x2="10" y1="21" y2="14"></line></svg></button></div></div></div></a><figcaption class="image-caption">Image by <a href="https://pixabay.com/users/ambquinn-4464111/?utm_source=link-attribution&amp;utm_medium=referral&amp;utm_campaign=image&amp;utm_content=8285565">Angela</a> from Pixabay</figcaption></figure></div><p><em><strong>How much can responsibly be known about a transaction before money moves?</strong></em> In real-time financial systems, this question is no longer theoretical. Payment infrastructures based on ISO 20022 messages, including pacs.008 credit transfers, operate under strict latency constraints. <strong>Institutions must decide whether to interrupt, flag, or allow a transaction using only the information available at that moment. Most contextual data arrives later, if at all.</strong></p><p>The prevailing belief is that fraud detection improves as data volume increases. More device fingerprints, more behavioral history, more external databases, more features. Yet in high-speed payment environments, this assumption collides with operational reality. <strong>Decisions must be made in milliseconds, often using only the transactional payload itself.</strong></p><p>The <strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments">Noctua API</a></strong> emerges from this tension. It is not built to prove fraud, nor to replicate large-scale surveillance models. It is built around a narrower question: <em><strong>what is the potential for defensible suspicion when only small, structured transactional data is available?</strong></em></p><p>This question matters now because the expansion of ISO 20022 has increased semantic richness in payments [1][2]. The pacs.008 message contains identifiers, timestamps, parties, currencies, and contextual descriptors. But expressiveness does not equal certainty. Mapping these fields to risk signals is an interpretive act, not a discovery of ground truth. <strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments">Noctua</a></strong> was designed to operate precisely within that constraint.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments&quot;,&quot;text&quot;:&quot;Try here!&quot;,&quot;action&quot;:null,&quot;class&quot;:&quot;button-wrapper&quot;}" data-component-name="ButtonCreateButton"><a class="button primary button-wrapper" href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments"><span>Try here!</span></a></p><h3>How People Tend to Solve It</h3><p>In most financial institutions, antifraud systems respond to uncertainty with expansion. More data sources are integrated. Device intelligence is layered on top of transactional data. Behavioral biometrics and third-party risk feeds are incorporated. Machine learning models are retrained to optimize performance metrics such as AUC, precision, recall, or false positive rates.</p><p>These approaches are understandable. <strong>Fraud is adaptive, and static systems fail.</strong> Expanding context appears rational, particularly when losses are visible and regulatory pressure is high [3]. In large banks, dedicated teams manage feature pipelines that ingest hundreds or thousands of variables per transaction.</p><p>This strategy partially works. <strong>Large datasets can improve detection in stable environments. However, it introduces structural problems.</strong> First, latency increases. Second, interpretability degrades. Third, institutions become dependent on external signals that may not be uniformly available across jurisdictions or channels.</p><p>More importantly, the expansion model quietly shifts the epistemic posture of the system. Instead of asking what can be known, it assumes that enough accumulation will eventually approximate certainty. As documented in critiques of algorithmic decision-making, this often produces confidence without commensurate understanding [4][5]. Scores are optimized, but responsibility becomes opaque.</p><p>In real-time credit transfers, particularly those using pacs.008 structures, many of these external signals are unavailable at decision time. What remains is the message itself. The question then becomes whether it is possible to extract meaningful risk articulation from that constrained semantic surface.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments&quot;,&quot;text&quot;:&quot;Try here!&quot;,&quot;action&quot;:null,&quot;class&quot;:&quot;button-wrapper&quot;}" data-component-name="ButtonCreateButton"><a class="button primary button-wrapper" href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments"><span>Try here!</span></a></p><h3>Better Practices: The Small Data Posture</h3><p>Noctua adopts a small data approach grounded in the <strong><a href="https://www.amazon.com/dp/B0GL9VJP94">Minerva framework</a></strong>. Small data does not mean simplistic data. It refers to semantically dense, immediately available information that can support provisional suspicion without fabricating intent.</p><p>Consider the following payload:</p><div class="highlighted_code_block" data-attrs="{&quot;language&quot;:&quot;json&quot;,&quot;nodeId&quot;:&quot;5d9b6225-152b-499d-ac19-47694b09066e&quot;}" data-component-name="HighlightedCodeBlockToDOM"><pre class="shiki"><code class="language-json">{
  "datetime": "2026-02-18T10:59:59.999",
  "sender_name": "John Doe",
  "sender_account_type": "SVGS",
  "receiver_name": "Joana Doe",
  "receiver_account_type": "SVGS",
  "country_code": "USA",
  "channel": "IPAY",
  "transaction_type": "DEPO",
  "priority": "NORM",
  "currency": "USD",
  "amount": 10.01
}</code></pre></div><p>From this limited structure, <strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments">Noctua</a></strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments"> </a>produced a risk score of 3.27 on a scale where 0 represents minimal risk and 10 represents extreme risk. More importantly, it articulated risk factors rather than issuing a verdict. It identified contextual dimensions such as business hours, transaction channel, currency prevalence, economy size, and transaction amount.</p><p>The significance lies not in the numeric output, but in the articulation. <strong>Each factor is traceable to observable attributes. The system does not claim knowledge of intent, historical fraud patterns, or external behavioral data. It translates structured fields into interpretable signals.</strong></p><p>For example, <em>country_code</em> interacts with macroeconomic exposure. Large, high-volume economies statistically attract more fraudulent attempts due to scale effects [3]. Channel information such as <em>IPAY</em> introduces exposure to online vectors. Amount size relative to currency norms affects threshold gaming patterns. None of these signals assert fraud. They express structured tension.</p><p>This design reflects a key ISO 20022 insight: <em><strong>messages encode semantic roles, not conclusions</strong></em> [1][2]. pacs.008 identifies debtor, creditor, amounts, settlement context, and instruction metadata. Noctua treats these elements as potential epistemic anchors. It avoids constructing behavioral narratives beyond what the message can support.</p><p>The trade-off is explicit. Small data models cannot detect complex longitudinal laundering patterns or network-level layering without external graph data. They cannot infer hidden relationships or synthetic identities. However, they preserve interpretability, latency compliance, and institutional accountability. The system&#8217;s limits are visible rather than concealed behind high-dimensional embeddings.</p><p>In banking environments, this approach can be particularly relevant for instant payment rails, cross-border corridors with limited shared data, and institutions seeking defensible first-layer screening before deeper review.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments&quot;,&quot;text&quot;:&quot;Try here!&quot;,&quot;action&quot;:null,&quot;class&quot;:&quot;button-wrapper&quot;}" data-component-name="ButtonCreateButton"><a class="button primary button-wrapper" href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments"><span>Try here!</span></a></p><h3>Conclusions</h3><p><strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments">Noctua</a></strong> does not solve fraud. It reframes the problem. The central question was whether meaningful suspicion can emerge from small, structured transactional data. The answer is conditional. Yes, signals can be articulated. Yes, risk gradients can be estimated. But no, certainty cannot be manufactured from limited context.</p><p>More data may eventually refine interpretation, but at decision time, the pacs.008 message defines the epistemic boundary. Operating within that boundary requires restraint. The value of <strong><a href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments">Noctua</a></strong> lies in making that boundary explicit.</p><p>What remains unresolved is how such small-data systems should interact with larger antifraud ecosystems. <em><strong>Should they serve as first-pass filters, explainability layers, or standalone screening tools?</strong></em> These architectural questions depend on institutional priorities and regulatory contexts.</p><p>What can reasonably be said is that small data, when treated with semantic discipline, can support defensible suspicion without collapsing into automated certainty. In an era where metrics often replace decisions, this distinction matters.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments&quot;,&quot;text&quot;:&quot;Try here!&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://rapidapi.com/augsmachado/api/noctua-api-transaction-risk-layer-for-structured-payments"><span>Try here!</span></a></p><div><hr></div><h3>Bibliographic References</h3><p>[1] ISO. ISO 20022: a single standardization approach (methodology, process, repository) to be used by all financial standards initiatives. 2004.<br>[2] SWIFT. ISO 20022: standards. 2026.<br>[3] Bank for International Settlements (BIS). Digital fraud and banking: supervisory and financial stability implications. 2023.<br>[4] O&#8217;NEIL, C. Weapons of Math Destruction. Crown Publishing Group, 2016.<br>[5] PASQUALE, F. The Black Box Society. Harvard University Press, 2015.</p>]]></content:encoded></item><item><title><![CDATA[A Minimal Format Conversion API as an Experimental Layer for Data Interoperability]]></title><description><![CDATA[This working paper investigates how a minimal API dedicated to XML and JSON conversion can function as an experimental layer for studying data interoperability in modern systems.]]></description><link>https://www.datas2.com/p/a-minimal-format-conversion-api-as</link><guid isPermaLink="false">https://www.datas2.com/p/a-minimal-format-conversion-api-as</guid><dc:creator><![CDATA[Augusto Machado]]></dc:creator><pubDate>Mon, 29 Dec 2025 22:45:26 GMT</pubDate><enclosure url="https://substackcdn.com/image/fetch/$s_!yQR2!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fcbb298c2-de31-43e3-8329-922727bc2caf_1920x1280.jpeg" length="0" type="image/jpeg"/><content:encoded><![CDATA[<div class="captioned-image-container"><figure><a 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stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-maximize2 lucide-maximize-2"><polyline points="15 3 21 3 21 9"></polyline><polyline points="9 21 3 21 3 15"></polyline><line x1="21" x2="14" y1="3" y2="10"></line><line x1="3" x2="10" y1="21" y2="14"></line></svg></button></div></div></div></a></figure></div><p>This working paper investigates how a minimal API dedicated to XML and JSON conversion can function as an experimental layer for studying data interoperability in modern systems. Rather than focusing on performance optimization or comprehensive schema management, the paper explores the role of simple, stateless format transformation services in contemporary data pipelines.</p><p>The investigation is applied and conceptual in nature. It examines a FastAPI-based utility that exposes basic endpoints for converting XML to JSON and JSON to XML, alongside a status endpoint for observability. The goal is not to propose a universal solution for data serialization, but to reflect on how constrained utilities can support experimentation, learning, and integration across heterogeneous systems where legacy and modern formats coexist.</p><p>As a working paper, this document does not claim general applicability or production readiness. It presents observations derived from the current implementation, emphasizing design simplicity, explicit error handling, and ease of use. The paper aims to prepare the reader to think about format conversion not as a solved problem, but as a recurring interface challenge that reveals deeper questions about data structure, validation, and semantic loss across representations.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/subscribe?&quot;,&quot;text&quot;:&quot;Subscribe now&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/subscribe?"><span>Subscribe now</span></a></p><div><hr></div><h2><strong>General Information</strong></h2><h3><strong>Motivation</strong></h3><p>Despite the widespread adoption of JSON as a dominant data interchange format, XML remains deeply embedded in legacy systems, enterprise integrations, and standardized protocols. Engineers frequently encounter scenarios where XML and JSON must coexist, requiring reliable conversion between formats. The motivation behind this investigation is to explore whether a deliberately simple API can reduce friction in these scenarios while making the limitations of format conversion more visible.</p><p>The <strong><a href="https://rapidapi.com/augsmachado/api/xml-to-json-api/">XML/JSON Utility API</a></strong> was conceived as a public utility rather than a full-featured transformation engine. Its primary intent is to offer a lightweight interface for experimentation, prototyping, and educational use.</p><h3><strong>Scope and assumptions</strong></h3><p>This work focuses exclusively on syntactic conversion between XML and JSON representations. It assumes well-formed input and does not enforce schemas, namespaces, or semantic validation beyond basic parsing. The API operates in a stateless manner and assumes non-adversarial usage.</p><p>The service is positioned as an auxiliary tool rather than a core integration platform, and it is expected that consumers understand the potential ambiguity involved in mapping hierarchical XML structures to JSON objects and back.</p><h3><strong>Non-goals</strong></h3><p>This paper does not aim to address schema inference, XML namespaces, attribute preservation strategies, or round-trip fidelity guarantees. It does not attempt to standardize XML-to-JSON mappings or compare alternative serialization formats. Performance benchmarking, security hardening, and large-payload handling are explicitly out of scope.</p><h3><strong>Status of the investigation</strong></h3><p>The system is experimental and subject to change. Endpoints, behavior, and implementation details may evolve without notice. Observations reflect the current state of the API rather than a finalized or stabilized design.</p><div><hr></div><h2><strong>Sections</strong></h2><h3><strong>Background and related context</strong></h3><p>Data interchange formats have evolved alongside computing paradigms. XML emerged as a flexible, self-describing format suited for document-oriented and enterprise workflows, while JSON gained prominence through its alignment with web applications and lightweight data exchange. Conversion between these formats is often treated as a mechanical task, yet practical experience shows that such transformations can introduce ambiguity and information loss.</p><p>Utility APIs that expose conversion functionality provide an opportunity to examine these issues explicitly, rather than hiding them within libraries or monolithic integration systems.</p><h3><strong>Conceptual model</strong></h3><p>The <strong><a href="https://rapidapi.com/augsmachado/api/xml-to-json-api/">XML/JSON Utility API</a></strong> follows a straightforward conceptual model. Clients submit raw XML or JSON payloads to dedicated endpoints, and the service returns the corresponding transformed representation. The API does not persist state, enforce authentication, or apply schema constraints, reinforcing its role as a transient transformation layer.</p><p>A <code>/status</code> endpoint provides minimal operational insight, separating service liveness from functional correctness. CORS is enabled to facilitate experimentation across environments, further emphasizing accessibility over restriction.</p><h3><strong>Observations on transformation behavior</strong></h3><p>One observation arising from the implementation is that structural clarity in input data strongly influences the quality of the output. Simple, well-nested XML structures map cleanly to JSON, while more complex constructs&#8212;such as attributes, mixed content, or repeated elements&#8212;highlight the inherent subjectivity of conversion rules.</p><p>Error handling plays a critical role in this context. By returning explicit parsing errors and details, the API exposes failure modes that might otherwise remain implicit, encouraging users to reason about data quality rather than assuming seamless interoperability.</p><h3><strong>Trade-offs and limitations</strong></h3><p>The simplicity of the API is both its strength and its limitation. While it lowers the barrier to entry and supports rapid experimentation, it deliberately avoids addressing deeper concerns such as semantic preservation or schema alignment. This trade-off reinforces the idea that format conversion alone does not resolve interoperability challenges; it merely surfaces them.</p><div><hr></div><h2><strong>Status &amp; Next Steps</strong></h2><p>This work is currently exploratory and applied. Open questions include how users interpret lossy conversions, how schema-aware extensions could alter behavior, and whether explicit conversion policies improve or hinder usability.</p><p>Possible future directions involve experimenting with schema validation, namespace handling, configurable mapping strategies, and comparative studies between utility APIs and embedded library approaches. These questions remain intentionally open, reinforcing the role of this API as a laboratory rather than a definitive solution.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/p/a-minimal-format-conversion-api-as?utm_source=substack&utm_medium=email&utm_content=share&action=share&quot;,&quot;text&quot;:&quot;Share&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/p/a-minimal-format-conversion-api-as?utm_source=substack&utm_medium=email&utm_content=share&action=share"><span>Share</span></a></p><div><hr></div><h2><strong>Bibliographic References</strong></h2><ul><li><p>Fielding, R. <em>Architectural Styles and the Design of Network-based Software Architectures.</em> Doctoral Dissertation, 2000.</p></li><li><p>Bray, T. et al. <em>Extensible Markup Language (XML) 1.0.</em> W3C Recommendation, 2008.</p></li><li><p>ECMA International. <em>The JSON Data Interchange Syntax.</em> ECMA-404, 2017.</p></li><li><p>Kleppmann, M. <em>Designing Data-Intensive Applications.</em> O&#8217;Reilly Media, 2017.</p></li><li><p>Python Software Foundation. <em>xmltodict and dicttoxml Documentation.</em>, 2023.</p></li></ul>]]></content:encoded></item><item><title><![CDATA[A Lightweight Timezone and Geospatial API as an Experimental Infrastructure for Temporal Reasoning]]></title><description><![CDATA[This working paper investigates how a lightweight, API-based service for timezone and city lookup can serve as an experimental infrastructure for reasoning about time, geography, and temporal boundaries in distributed systems.]]></description><link>https://www.datas2.com/p/a-lightweight-timezone-and-geospatial</link><guid isPermaLink="false">https://www.datas2.com/p/a-lightweight-timezone-and-geospatial</guid><dc:creator><![CDATA[Augusto Machado]]></dc:creator><pubDate>Mon, 29 Dec 2025 21:51:40 GMT</pubDate><enclosure url="https://substackcdn.com/image/fetch/$s_!LhWJ!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg" length="0" type="image/jpeg"/><content:encoded><![CDATA[<div class="captioned-image-container"><figure><a class="image-link image2 is-viewable-img" target="_blank" href="https://substackcdn.com/image/fetch/$s_!LhWJ!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg" data-component-name="Image2ToDOM"><div class="image2-inset"><picture><source type="image/webp" srcset="https://substackcdn.com/image/fetch/$s_!LhWJ!,w_424,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 424w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_848,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 848w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_1272,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 1272w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 1456w" sizes="100vw"><img src="https://substackcdn.com/image/fetch/$s_!LhWJ!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg" width="1280" height="905" data-attrs="{&quot;src&quot;:&quot;https://substack-post-media.s3.amazonaws.com/public/images/c4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg&quot;,&quot;srcNoWatermark&quot;:null,&quot;fullscreen&quot;:null,&quot;imageSize&quot;:null,&quot;height&quot;:905,&quot;width&quot;:1280,&quot;resizeWidth&quot;:null,&quot;bytes&quot;:null,&quot;alt&quot;:&quot;Free Clocks Time photo and picture&quot;,&quot;title&quot;:null,&quot;type&quot;:null,&quot;href&quot;:null,&quot;belowTheFold&quot;:false,&quot;topImage&quot;:true,&quot;internalRedirect&quot;:null,&quot;isProcessing&quot;:false,&quot;align&quot;:null,&quot;offset&quot;:false}" class="sizing-normal" alt="Free Clocks Time photo and picture" title="Free Clocks Time photo and picture" srcset="https://substackcdn.com/image/fetch/$s_!LhWJ!,w_424,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 424w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_848,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 848w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_1272,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 1272w, https://substackcdn.com/image/fetch/$s_!LhWJ!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fc4e7c470-e1b1-42e2-afe6-6796920ac154_1280x905.jpeg 1456w" sizes="100vw" fetchpriority="high"></picture><div class="image-link-expand"><div class="pencraft pc-display-flex pc-gap-8 pc-reset"><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container restack-image"><svg role="img" width="20" height="20" viewBox="0 0 20 20" fill="none" stroke-width="1.5" stroke="var(--color-fg-primary)" stroke-linecap="round" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg"><g><title></title><path d="M2.53001 7.81595C3.49179 4.73911 6.43281 2.5 9.91173 2.5C13.1684 2.5 15.9537 4.46214 17.0852 7.23684L17.6179 8.67647M17.6179 8.67647L18.5002 4.26471M17.6179 8.67647L13.6473 6.91176M17.4995 12.1841C16.5378 15.2609 13.5967 17.5 10.1178 17.5C6.86118 17.5 4.07589 15.5379 2.94432 12.7632L2.41165 11.3235M2.41165 11.3235L1.5293 15.7353M2.41165 11.3235L6.38224 13.0882"></path></g></svg></button><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container view-image"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-maximize2 lucide-maximize-2"><polyline points="15 3 21 3 21 9"></polyline><polyline points="9 21 3 21 3 15"></polyline><line x1="21" x2="14" y1="3" y2="10"></line><line x1="3" x2="10" y1="21" y2="14"></line></svg></button></div></div></div></a></figure></div><p>This working paper investigates how a lightweight, API-based service for timezone and city lookup can serve as an experimental infrastructure for reasoning about time, geography, and temporal boundaries in distributed systems. Rather than addressing timekeeping accuracy or proposing a universal timezone solution, the paper explores how constrained geospatial abstractions&#8212;such as region bounding boxes, proximity queries, and UTC offsets&#8212;can be operationalized through a simple HTTP interface.</p><p>The investigation is applied and exploratory in nature. It examines a FastAPI microservice that exposes timezone regions, cities, and spatial relationships through authenticated endpoints, focusing on design choices that prioritize clarity, inspectability, and ease of experimentation over completeness or real-time guarantees. The paper does not attempt to generalize findings across all temporal systems, nor does it evaluate performance or correctness against authoritative timezone databases.</p><p>As a working paper, this document presents observations derived from the current implementation rather than finalized conclusions. It frames questions about how developers and analysts reason about timezones when given simplified but explicit models, and how such models can support learning, prototyping, and exploratory analysis. The goal is to prepare the reader to think critically about temporal abstractions in software systems, not to prescribe a definitive solution.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/subscribe?&quot;,&quot;text&quot;:&quot;Subscribe now&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/subscribe?"><span>Subscribe now</span></a></p><div><hr></div><h2><strong>General Information</strong></h2><h3><strong>Motivation</strong></h3><p>Timezones are a persistent source of complexity in distributed systems, analytics pipelines, and user-facing applications. Despite extensive documentation and standardized databases, errors related to offsets, daylight saving time, and geographic boundaries remain common. The motivation behind this investigation is to explore whether a deliberately simplified, query-oriented API can make temporal reasoning more explicit and approachable for practitioners.</p><p>The <strong><a href="https://rapidapi.com/augsmachado/api/timestamp-api">Timestamp API</a></strong> was designed as a public utility rather than a production-grade service. Its purpose is to provide a concrete, inspectable layer through which users can explore how time, location, and regional boundaries interact, without embedding complex timezone logic directly into each application.</p><h3><strong>Scope and assumptions</strong></h3><p>This work focuses on static timezone regions, city metadata, and geospatial proximity queries derived from predefined datasets. It assumes that timezone boundaries can be approximated through region groupings and bounding boxes, and that users are aware of the limitations inherent in such approximations.</p><p>The API is treated as an exploratory interface. It assumes moderate, non-adversarial usage and does not guarantee real-time correctness with respect to political or legal changes in timezone definitions.</p><h3><strong>Non-goals</strong></h3><p>This paper does not aim to replace authoritative timezone libraries, provide historical timezone transitions, or guarantee legal or calendrical accuracy. It does not address leap seconds, historical boundary changes, or fine-grained polygon-based timezone mapping. High availability, performance benchmarking, and production hardening are explicitly out of scope.</p><h3><strong>Status of the investigation</strong></h3><p>The system is considered experimental. Endpoints, data representations, and assumptions may change without notice. Observations reflect the current state of the implementation rather than a stable or finalized design.</p><div><hr></div><h2><strong>Sections</strong></h2><h3><strong>Background and related context</strong></h3><p>Handling time correctly has long been recognized as one of the hardest problems in software engineering. Traditional approaches rely on comprehensive libraries that abstract away complexity but often obscure underlying assumptions. In contrast, exposing time-related data through explicit queries can surface those assumptions and make trade-offs more visible to users.</p><p>APIs that combine geospatial queries with timezone metadata occupy an intermediate space between raw libraries and fully managed time services. They offer structure without complete encapsulation.</p><h3><strong>Conceptual model</strong></h3><p>The Timestamp API is built around a simple conceptual model: timezones are represented as regions with approximate geographic bounds, and cities are treated as points with associated UTC offsets and DST flags. Queries operate over this model to answer questions such as which region contains a coordinate, which cities are nearest to a point, or which locations share a given offset.</p><p>FastAPI provides the HTTP interface layer, while API key enforcement defines a clear boundary between public visibility and controlled access. The open <code>/status</code> endpoint serves as a minimal liveness indicator, reinforcing the distinction between operational health and data correctness.</p><h3><strong>Querying time through space</strong></h3><p>A central observation from the implementation is that many timezone-related questions are inherently spatial. By framing time queries as geospatial operations&#8212;nearest city, region containment, radius-based search&#8212;the API encourages users to reason about time as a property attached to location rather than as an abstract offset alone.</p><p>This approach simplifies certain classes of questions while deliberately excluding others. Precision is traded for conceptual clarity.</p><h3><strong>Observations and limitations</strong></h3><p>Several limitations emerge from this design. Bounding boxes do not accurately represent irregular timezone borders, and DST status may change independently of geographic position. However, these constraints are visible rather than hidden, allowing users to reason about error margins explicitly.</p><p>The uniform requirement for API keys highlights access control as part of the experimental surface, while the lack of persistence or caching emphasizes stateless interaction. Rather than solving all timezone problems, the API exposes a controlled subset that can be interrogated and questioned.</p><div><hr></div><h2><strong>Status &amp; Next Steps</strong></h2><p>This work is currently exploratory and applied. Open questions include how users interpret approximate timezone regions, how such APIs influence error rates in downstream systems, and whether explicit uncertainty improves or hinders adoption.</p><p>Possible future directions include comparing bounding-box approaches with polygon-based models, introducing temporal versioning, and studying how developers misuse or overtrust timezone abstractions. These questions remain intentionally open, reinforcing the role of this API as a laboratory rather than a definitive solution.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/p/a-lightweight-timezone-and-geospatial?utm_source=substack&utm_medium=email&utm_content=share&action=share&quot;,&quot;text&quot;:&quot;Share&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/p/a-lightweight-timezone-and-geospatial?utm_source=substack&utm_medium=email&utm_content=share&action=share"><span>Share</span></a></p><div><hr></div><h2><strong>Bibliographic References</strong></h2><ul><li><p>Eggert, P.; Olson, A. <em>The IANA Time Zone Database.</em> IANA, Documentation.</p></li><li><p>Fielding, R. <em>Architectural Styles and the Design of Network-based Software Architectures.</em> Doctoral Dissertation, 2000.</p></li><li><p>Kleppmann, M. <em>Designing Data-Intensive Applications.</em> O&#8217;Reilly Media, 2017.</p></li><li><p>Python Software Foundation. <em>zoneinfo &#8212; IANA Time Zone Support.</em>, Python Documentation, 2023.</p></li><li><p>Postel, J. <em>Robustness Principle.</em> RFC 793, 1981.</p></li></ul>]]></content:encoded></item><item><title><![CDATA[A Public Scraping API as an Experimental Layer for Market Data Exploration]]></title><description><![CDATA[This working paper investigates how a centralized, API-based scraping service can be used as an experimental layer for accessing and exploring large-scale e-commerce data without exposing end users to the operational complexity of scraping itself.]]></description><link>https://www.datas2.com/p/a-public-scraping-api-as-an-experimental</link><guid isPermaLink="false">https://www.datas2.com/p/a-public-scraping-api-as-an-experimental</guid><dc:creator><![CDATA[Augusto Machado]]></dc:creator><pubDate>Mon, 29 Dec 2025 21:44:13 GMT</pubDate><enclosure url="https://substackcdn.com/image/fetch/$s_!2-B1!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png" length="0" type="image/jpeg"/><content:encoded><![CDATA[<div class="captioned-image-container"><figure><a class="image-link image2 is-viewable-img" target="_blank" href="https://substackcdn.com/image/fetch/$s_!2-B1!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png" data-component-name="Image2ToDOM"><div class="image2-inset"><picture><source type="image/webp" srcset="https://substackcdn.com/image/fetch/$s_!2-B1!,w_424,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 424w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_848,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 848w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_1272,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 1272w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 1456w" sizes="100vw"><img src="https://substackcdn.com/image/fetch/$s_!2-B1!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png" width="1280" height="853" data-attrs="{&quot;src&quot;:&quot;https://substack-post-media.s3.amazonaws.com/public/images/f9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png&quot;,&quot;srcNoWatermark&quot;:null,&quot;fullscreen&quot;:null,&quot;imageSize&quot;:null,&quot;height&quot;:853,&quot;width&quot;:1280,&quot;resizeWidth&quot;:null,&quot;bytes&quot;:1553972,&quot;alt&quot;:null,&quot;title&quot;:null,&quot;type&quot;:&quot;image/png&quot;,&quot;href&quot;:null,&quot;belowTheFold&quot;:false,&quot;topImage&quot;:true,&quot;internalRedirect&quot;:&quot;https://www.datas2.com/i/182903705?img=https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png&quot;,&quot;isProcessing&quot;:false,&quot;align&quot;:null,&quot;offset&quot;:false}" class="sizing-normal" alt="" srcset="https://substackcdn.com/image/fetch/$s_!2-B1!,w_424,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 424w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_848,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 848w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_1272,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 1272w, https://substackcdn.com/image/fetch/$s_!2-B1!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Ff9124c41-c16f-4521-8dcc-0324032cf2b9_1280x853.png 1456w" sizes="100vw" fetchpriority="high"></picture><div class="image-link-expand"><div class="pencraft pc-display-flex pc-gap-8 pc-reset"><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container restack-image"><svg role="img" width="20" height="20" viewBox="0 0 20 20" fill="none" stroke-width="1.5" stroke="var(--color-fg-primary)" stroke-linecap="round" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg"><g><title></title><path d="M2.53001 7.81595C3.49179 4.73911 6.43281 2.5 9.91173 2.5C13.1684 2.5 15.9537 4.46214 17.0852 7.23684L17.6179 8.67647M17.6179 8.67647L18.5002 4.26471M17.6179 8.67647L13.6473 6.91176M17.4995 12.1841C16.5378 15.2609 13.5967 17.5 10.1178 17.5C6.86118 17.5 4.07589 15.5379 2.94432 12.7632L2.41165 11.3235M2.41165 11.3235L1.5293 15.7353M2.41165 11.3235L6.38224 13.0882"></path></g></svg></button><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container view-image"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-maximize2 lucide-maximize-2"><polyline points="15 3 21 3 21 9"></polyline><polyline points="9 21 3 21 3 15"></polyline><line x1="21" x2="14" y1="3" y2="10"></line><line x1="3" x2="10" y1="21" y2="14"></line></svg></button></div></div></div></a></figure></div><p></p><p>This working paper investigates how a centralized, API-based scraping service can be used as an experimental layer for accessing and exploring large-scale e-commerce data without exposing end users to the operational complexity of scraping itself. Rather than focusing on scraping techniques or reverse engineering, the paper examines the architectural and design implications of wrapping scraping logic behind a controlled HTTP interface.</p><p>The investigation is applied and exploratory in nature. It uses the <strong><a href="https://rapidapi.com/augsmachado/api/ebay-scraper-api">eBay Scraper API</a></strong> as a concrete case to reflect on how concerns such as authentication, concurrency control, retries, and error normalization can be abstracted away from consumers, enabling faster experimentation and prototyping. The paper does not aim to evaluate scraping legality, long-term robustness, or competitive performance against official APIs.</p><p>As a working paper, this document does not present finalized results or generalized claims. Instead, it frames a set of design decisions, constraints, and observed behaviors that emerge when scraping is treated as a shared infrastructure component rather than an ad-hoc script. The intent is to stimulate reflection on scraping-as-a-service as a pedagogical and research-oriented construct, particularly in contexts where official APIs are limited, unavailable, or insufficient for exploratory analysis.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/subscribe?&quot;,&quot;text&quot;:&quot;Subscribe now&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/subscribe?"><span>Subscribe now</span></a></p><div><hr></div><h1><strong>General Information</strong></h1><h3><strong>Motivation</strong></h3><p>Scraping remains a common but fragile technique in data engineering and market analysis. In practice, many teams rely on isolated scripts with inconsistent error handling, duplicated logic, and little observability. The motivation behind this investigation is to explore whether centralizing scraping behind a thin API layer can reduce this fragmentation and make exploratory access to market data more systematic and reusable.</p><p>The eBay Scraper API was designed as a public utility rather than a production-grade service. Its primary goal is to support experiments, prototypes, and research workflows that require access to product, seller, and pricing information without embedding scraping logic directly into each consumer application.</p><h3><strong>Scope and assumptions</strong></h3><p>This work focuses on HTTP-based scraping of publicly accessible eBay product and seller pages, exposed through a REST API with API key enforcement. It assumes non-adversarial usage, moderate traffic, and consumers who are aware that data completeness and stability are not guaranteed.</p><p>The API is treated as a black box from the client perspective. The internal scraping mechanics are not analyzed in detail, as the investigation centers on interface design, control boundaries, and usage patterns rather than scraping internals.</p><h3><strong>Non-goals</strong></h3><p>This paper does not aim to benchmark scraping performance, ensure long-term availability, or compare results against official eBay APIs. It does not address legal, ethical, or contractual considerations of scraping beyond acknowledging their existence. Real-time guarantees, strict SLAs, and high-availability architectures are explicitly out of scope.</p><h3><strong>Status of the investigation</strong></h3><p>The system is considered experimental and best-effort. Endpoints, payload shapes, and behavior may change without notice. Findings reflect observations from the current version of the API rather than a stable or finalized design.</p><div><hr></div><h1><strong>Sections</strong></h1><h3><strong>Background and related context</strong></h3><p>In the absence of comprehensive official APIs, scraping has historically filled the gap for accessing online market data. However, scraping scripts tend to be tightly coupled to page structure, lack standardized error handling, and are difficult to share across teams. Wrapping scraping logic in an API introduces a layer of indirection that can standardize access while exposing limitations more transparently.</p><h3><strong>Conceptual model</strong></h3><p>The API follows a simple conceptual model: authenticated HTTP requests trigger controlled scraping operations, which return normalized JSON responses. Authentication is enforced through a base64-encoded API key passed via headers, and all protected endpoints share the same access control mechanism.</p><p>Endpoints are organized around user intent rather than scraping mechanics. Searching for products, retrieving product details, and querying sellers are treated as first-class operations, regardless of how many pages or domains are involved behind the scenes. Status endpoints remain open to support basic observability and liveness checks.</p><h3><strong>Concurrency, retries, and normalization</strong></h3><p>One of the core design choices is centralizing concurrency control and retry logic within the API itself. This shifts responsibility away from clients, who no longer need to manage parallel requests, transient failures, or partial results. Errors are normalized into consistent HTTP responses, allowing consumers to reason about failure modes without understanding scraping internals.</p><p>This design introduces a clear trade-off. While clients gain simplicity, they also relinquish fine-grained control over scraping behavior. The API becomes both an enabler and a constraint.</p><h3><strong>Observations and limitations</strong></h3><p>Several observations arise from this approach. Centralization reduces duplicated effort and lowers the barrier to experimentation, especially for non-specialist users. At the same time, the API inherits the fragility of scraping itself. Changes in upstream page structure can affect all consumers simultaneously, reinforcing the importance of explicit instability disclaimers.</p><p>Rate limiting and API key enforcement provide basic protection, but their in-memory nature highlights scaling limitations in distributed deployments. Rather than hiding these constraints, the system exposes them as part of the learning experience.</p><div><hr></div><h1><strong>Status &amp; Next Steps</strong></h1><p>This work is currently exploratory and applied. Open questions include how consumers interpret partial or inconsistent data, how static validation of queries or requests could be introduced, and how scraping volatility impacts downstream analytical workflows. <strong><a href="https://rapidapi.com/augsmachado/api/ebay-scraper-api">Access the API here</a></strong>.</p><p>Possible future directions include comparing centralized scraping APIs with event-based ingestion pipelines, experimenting with cache-aware responses, and studying how consumers misuse or overtrust scraped data. These questions remain intentionally open, reinforcing the role of this system as a living laboratory rather than a finished solution.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/p/a-public-scraping-api-as-an-experimental?utm_source=substack&utm_medium=email&utm_content=share&action=share&quot;,&quot;text&quot;:&quot;Share&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/p/a-public-scraping-api-as-an-experimental?utm_source=substack&utm_medium=email&utm_content=share&action=share"><span>Share</span></a></p><div><hr></div><h1><strong>Bibliographic References</strong></h1><ul><li><p>Fielding, R. <em>Architectural Styles and the Design of Network-based Software Architectures.</em> Doctoral Dissertation, 2000.</p></li><li><p>Kleppmann, M. <em>Designing Data-Intensive Applications.</em> O&#8217;Reilly Media, 2017.</p></li><li><p>Mitchell, R. <em>Web Scraping with Python.</em> O&#8217;Reilly Media, 2018.</p></li><li><p>Richardson, L.; Ruby, S. <em>RESTful Web Services.</em> O&#8217;Reilly Media, 2007.</p></li><li><p>Mozilla Developer Network. <em>HTTP Status Codes and API Design.</em>, Documentation, 2023.</p></li></ul>]]></content:encoded></item><item><title><![CDATA[A Lightweight Public Transport Stops API as a Data Engineering Laboratory]]></title><description><![CDATA[This working paper investigates how a lightweight, read-only API built on top of open public transport data can function as a practical laboratory for data engineering, spatial querying, and applied analytics.]]></description><link>https://www.datas2.com/p/a-lightweight-public-transport-stops</link><guid isPermaLink="false">https://www.datas2.com/p/a-lightweight-public-transport-stops</guid><dc:creator><![CDATA[Augusto Machado]]></dc:creator><pubDate>Mon, 29 Dec 2025 21:32:54 GMT</pubDate><enclosure url="https://substackcdn.com/image/fetch/$s_!ta3r!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png" length="0" type="image/jpeg"/><content:encoded><![CDATA[<div class="captioned-image-container"><figure><a class="image-link image2 is-viewable-img" target="_blank" href="https://substackcdn.com/image/fetch/$s_!ta3r!,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png" data-component-name="Image2ToDOM"><div class="image2-inset"><picture><source type="image/webp" srcset="https://substackcdn.com/image/fetch/$s_!ta3r!,w_424,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 424w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_848,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 848w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_1272,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 1272w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_1456,c_limit,f_webp,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 1456w" sizes="100vw"><img src="https://substackcdn.com/image/fetch/$s_!ta3r!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png" width="1280" height="872" data-attrs="{&quot;src&quot;:&quot;https://substack-post-media.s3.amazonaws.com/public/images/35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png&quot;,&quot;srcNoWatermark&quot;:null,&quot;fullscreen&quot;:null,&quot;imageSize&quot;:null,&quot;height&quot;:872,&quot;width&quot;:1280,&quot;resizeWidth&quot;:null,&quot;bytes&quot;:1841118,&quot;alt&quot;:null,&quot;title&quot;:null,&quot;type&quot;:&quot;image/png&quot;,&quot;href&quot;:null,&quot;belowTheFold&quot;:false,&quot;topImage&quot;:true,&quot;internalRedirect&quot;:&quot;https://www.datas2.com/i/182902848?img=https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png&quot;,&quot;isProcessing&quot;:false,&quot;align&quot;:null,&quot;offset&quot;:false}" class="sizing-normal" alt="" srcset="https://substackcdn.com/image/fetch/$s_!ta3r!,w_424,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 424w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_848,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 848w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_1272,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 1272w, https://substackcdn.com/image/fetch/$s_!ta3r!,w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F35448c06-c533-4863-ae11-a1a6eb7584a9_1280x872.png 1456w" sizes="100vw" fetchpriority="high"></picture><div class="image-link-expand"><div class="pencraft pc-display-flex pc-gap-8 pc-reset"><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container restack-image"><svg role="img" width="20" height="20" viewBox="0 0 20 20" fill="none" stroke-width="1.5" stroke="var(--color-fg-primary)" stroke-linecap="round" stroke-linejoin="round" xmlns="http://www.w3.org/2000/svg"><g><title></title><path d="M2.53001 7.81595C3.49179 4.73911 6.43281 2.5 9.91173 2.5C13.1684 2.5 15.9537 4.46214 17.0852 7.23684L17.6179 8.67647M17.6179 8.67647L18.5002 4.26471M17.6179 8.67647L13.6473 6.91176M17.4995 12.1841C16.5378 15.2609 13.5967 17.5 10.1178 17.5C6.86118 17.5 4.07589 15.5379 2.94432 12.7632L2.41165 11.3235M2.41165 11.3235L1.5293 15.7353M2.41165 11.3235L6.38224 13.0882"></path></g></svg></button><button tabindex="0" type="button" class="pencraft pc-reset pencraft icon-container view-image"><svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="lucide lucide-maximize2 lucide-maximize-2"><polyline points="15 3 21 3 21 9"></polyline><polyline points="9 21 3 21 3 15"></polyline><line x1="21" x2="14" y1="3" y2="10"></line><line x1="3" x2="10" y1="21" y2="14"></line></svg></button></div></div></div></a></figure></div><p>This working paper investigates how a lightweight, read-only API built on top of open public transport data can function as a practical laboratory for data engineering, spatial querying, and applied analytics. Rather than focusing on performance optimization or production-grade guarantees, the study explores how minimal architectural choices&#8212;Parquet snapshots, in-process SQL engines, and simple HTTP interfaces&#8212;can enable meaningful experimentation and learning.</p><p>The work examines a thin JSON/HTTP wrapper around Auckland Transport&#8217;s bus stop dataset, designed to support exploratory use cases such as spatial proximity analysis, pagination, and identifier-based lookup. The goal is not to propose a generalized solution for geospatial APIs, but to reflect on the trade-offs involved in deliberately constrained systems intended for research, teaching, and prototyping.</p><p>This paper is exploratory and conceptual in nature, grounded in an applied implementation. It does not claim completeness, operational robustness, or external validity beyond its context. As a working paper, it presents observations, design decisions, and open questions that emerge from the implementation, rather than finalized results or prescriptive architectures. The intent is to invite reflection on how small, well-scoped data services can act as educational and experimental tools within the broader data engineering ecosystem.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/subscribe?&quot;,&quot;text&quot;:&quot;Subscribe now&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/subscribe?"><span>Subscribe now</span></a></p><div><hr></div><h1><strong>General Information</strong></h1><h3><strong>Motivation</strong></h3><p>Modern data engineering discourse often centers on large-scale, production-ready platforms, which can obscure the value of smaller, intentionally limited systems. The motivation behind this investigation is to understand how a simple API, built on open data and modest infrastructure, can still support meaningful experimentation with data access patterns, spatial queries, and system design.</p><p>The Auckland Bus Stops API was conceived as a public utility rather than a commercial or mission-critical service. Its purpose is to lower the barrier to entry for working with real-world transport data while maintaining transparency about its limitations.</p><h3><strong>Scope and assumptions</strong></h3><p>This work focuses exclusively on stop-level public transport data derived from a GTFS-based snapshot. It assumes periodic, but not guaranteed, data freshness and operates under the assumption that users are engaging with the API for learning, research, or prototyping purposes. Performance, availability, and strict correctness guarantees are explicitly out of scope.</p><h3><strong>Non-goals</strong></h3><p>This paper does not aim to design a full GTFS API, a real-time transport service, or a comprehensive GIS platform. Route planning, timetables, live vehicle tracking, and high-precision geospatial calculations are intentionally excluded. The system is not evaluated against production SLAs or scalability benchmarks.</p><h3><strong>Status of the investigation</strong></h3><p>The implementation is considered experimental and exploratory. Design choices are subject to change, and the findings presented here reflect the current state of the system rather than a finalized architecture.</p><div><hr></div><h1><strong>Sections</strong></h1><h3><strong>Conceptual model</strong></h3><p>At its core, the system is built around a deliberately simple mental model: a static snapshot of structured data stored in Parquet format, queried via SQL, and exposed through HTTP endpoints. The Parquet file represents a tabular view of bus stops, including identifiers, names, coordinates, and optional precomputed metric fields.</p><p>DuckDB is used as an embedded, in-memory query engine, providing SQL access without requiring an external database service. Each request establishes a lightweight connection, executes a parameterized query, and returns results in a JSON-friendly structure. This approach emphasizes transparency and inspectability over long-lived state or aggressive caching.</p><p>FastAPI acts as the interface layer, translating HTTP requests into constrained query patterns. The API surface is intentionally narrow, supporting pagination, name-based filtering, exact identifier lookup, and proximity queries based on a Haversine distance approximation.</p><h3><strong>Access control and operational boundaries</strong></h3><p>Although the API is public in intent, it is not anonymous. Access is gated through an API key provided via request headers, with a simple per-IP rate limiter enforced in memory. These mechanisms are not designed for adversarial environments but serve as soft boundaries that encourage responsible use and protect the service from accidental overload.</p><p>The choice of an in-memory rate limiter reflects a conscious trade-off. In scaled deployments, enforcement becomes instance-local, highlighting an important limitation of simplicity-first designs. Rather than resolving this with distributed state, the implementation surfaces the issue as a teaching point about scalability and control planes.</p><h3><strong>Spatial querying as approximation</strong></h3><p>Proximity queries are implemented using a Haversine-based distance calculation on latitude and longitude values. This method prioritizes conceptual clarity and sufficient accuracy for nearby-stop exploration over geospatial rigor. The system does not attempt to model complex projections or authoritative distance measurements, reinforcing its role as an exploratory tool rather than a GIS authority.</p><p>This choice illustrates a broader theme: in many applied data scenarios, approximate answers are acceptable when their limitations are clearly communicated.</p><h3><strong>Observations and trade-offs</strong></h3><p>Several observations emerge from the implementation. The combination of Parquet and DuckDB enables expressive querying with minimal infrastructure, making it suitable for rapid experimentation. At the same time, the lack of real-time guarantees and the reliance on snapshot data introduce uncertainty that must be explicitly acknowledged.</p><p>The API&#8217;s thinness becomes both its strength and its limitation. It encourages users to think critically about what is being abstracted away and what remains exposed. Rather than hiding complexity, the system frames it.</p><div><hr></div><h2><strong>Status &amp; Next Steps</strong></h2><p>The current state of this work is exploratory and applied. Open questions remain around how such a system behaves under moderate concurrency, how static validation of spatial queries could be introduced, and how educational users interpret and misuse proximity results. <strong><a href="https://rapidapi.com/augsmachado/api/auckland-bus-stops">Access the API here</a></strong>.</p><p>Possible future directions include experimenting with alternative rate-limiting strategies, introducing query introspection for cost estimation, and extending the model to compare approximate versus precise spatial methods. These directions are intentionally left open, reinforcing the role of this system as a living laboratory rather than a finished product.</p><p class="button-wrapper" data-attrs="{&quot;url&quot;:&quot;https://www.datas2.com/p/a-lightweight-public-transport-stops?utm_source=substack&utm_medium=email&utm_content=share&action=share&quot;,&quot;text&quot;:&quot;Share&quot;,&quot;action&quot;:null,&quot;class&quot;:null}" data-component-name="ButtonCreateButton"><a class="button primary" href="https://www.datas2.com/p/a-lightweight-public-transport-stops?utm_source=substack&utm_medium=email&utm_content=share&action=share"><span>Share</span></a></p><div><hr></div><h2><strong>Bibliographic References</strong></h2><ul><li><p>Melnik, S. et al. <em>Dremel: Interactive Analysis of Web-Scale Datasets.</em> VLDB, 2010.</p></li><li><p>Stonebraker, M.; Hellerstein, J. <em>What Goes Around Comes Around.</em> Readings in Database Systems, 2005.</p></li><li><p>DuckDB Labs. <em>DuckDB: An Embeddable Analytical Database.</em>, Documentation, 2023.</p></li><li><p>Google. <em>GTFS Static Overview.</em>, General Transit Feed Specification, 2023.</p></li><li><p>Fielding, R. <em>Architectural Styles and the Design of Network-based Software Architectures.</em> Doctoral Dissertation, 2000.</p></li></ul>]]></content:encoded></item></channel></rss>