https://huseyinkaplan.dev/insights/ Articles and notes on AI engineering, retrieval, evaluation and developer tools. en https://huseyinkaplan.dev/insights/smooth-without-the-wait/ https://huseyinkaplan.dev/insights/smooth-without-the-wait/ Sat, 17 Oct 2026 09:00:00 GMT How I added smooth scrolling and animated page changes to this static site: Lenis, native browser transitions, early preparation, and a test with 30 images still loading. Web Performance Browser APIs Animation https://huseyinkaplan.dev/insights/a-word-or-a-number/ https://huseyinkaplan.dev/insights/a-word-or-a-number/ Wed, 14 Oct 2026 09:00:00 GMT The same refund decision asked three ways, 540 times: a chat model, the same model held to a strict schema, and a decision model that returns a probability. Accuracy tied. The number found the one ticket I had labelled wrong. AI Agents LLM Evaluation TypeScript https://huseyinkaplan.dev/insights/a-results-page-on-someone-elses-storefront/ https://huseyinkaplan.dev/insights/a-results-page-on-someone-elses-storefront/ Tue, 13 Oct 2026 09:00:00 GMT One script that renders search results inside stores we do not host: what moved into a per-store config, how it mounts, and why old and new run side by side. E-commerce Search JavaScript Configuration https://huseyinkaplan.dev/insights/motion-graphics-written-as-code/ https://huseyinkaplan.dev/insights/motion-graphics-written-as-code/ Tue, 13 Oct 2026 09:00:00 GMT How the animated drawings on this site are made: SVG scenes on one clock, generated by short functions, written with Claude Code. With the real scenes running in the page. Motion Graphics SVG AI-Assisted Development https://huseyinkaplan.dev/insights/same-model-different-workflow/ https://huseyinkaplan.dev/insights/same-model-different-workflow/ Tue, 13 Oct 2026 09:00:00 GMT The written version of a session I gave my team on fixing bugs with an AI assistant: four steps, a context budget, the limits, and the demo I staged on purpose. AI-Assisted Development Debugging React https://huseyinkaplan.dev/insights/the-widget-that-worked-on-the-second-visit/ https://huseyinkaplan.dev/insights/the-widget-that-worked-on-the-second-visit/ Tue, 13 Oct 2026 09:00:00 GMT A blocked-notifications widget appeared only after a reload. Three small fixes: a race between two scripts, a cookie mistaken for the permission, and one state with three names. Web Push JavaScript Debugging https://huseyinkaplan.dev/insights/a-guard-against-saving-to-the-wrong-brand/ https://huseyinkaplan.dev/insights/a-guard-against-saving-to-the-wrong-brand/ Sun, 11 Oct 2026 09:00:00 GMT A tab showed one brand while the server session held another. The guard that blocks it, and a pass over 11 dashboards in a shared codebase. React Data Integrity Frontend Architecture https://huseyinkaplan.dev/insights/a-product-url-becomes-an-email-block/ https://huseyinkaplan.dev/insights/a-product-url-becomes-an-email-block/ Sun, 11 Oct 2026 09:00:00 GMT A product block inside a third-party email editor: mock data first, a wrap-once guard, a cookie-less request, an update loop and a context-aware inspector. React Email Editor Extensions https://huseyinkaplan.dev/insights/rolling-out-search-to-271-brands/ https://huseyinkaplan.dev/insights/rolling-out-search-to-271-brands/ Sun, 11 Oct 2026 09:00:00 GMT How a TypeScript CLI installed a new search on 271 of 272 brands: dry-run by default, status classes, backups, read-back vs independent verify, rollback. TypeScript Tooling Operations https://huseyinkaplan.dev/insights/building-an-admin-platform-from-scratch/ https://huseyinkaplan.dev/insights/building-an-admin-platform-from-scratch/ Tue, 06 Oct 2026 09:00:00 GMT How I built Revotas's new admin platform alone: CRM, support and billing on legacy APIs, plus a Turkish RAG assistant that cites sources or abstains. React RAG Product Engineering https://huseyinkaplan.dev/insights/compile-the-widget-dont-interpret-it/ https://huseyinkaplan.dev/insights/compile-the-widget-dont-interpret-it/ Tue, 06 Oct 2026 09:00:00 GMT How I built a no-code Deal of the Day builder: React state compiled into one self-contained script, previewed live in an iframe, with zero schema change. React No-code Web Widgets https://huseyinkaplan.dev/insights/push-that-opens-the-right-screen/ https://huseyinkaplan.dev/insights/push-that-opens-the-right-screen/ Tue, 06 Oct 2026 09:00:00 GMT React Native push taps arrive through three different APIs. One router, payload normalisation, token care, and a backend debug that went wrong. React Native Firebase Mobile https://huseyinkaplan.dev/insights/recommendations-in-the-stores-own-design/ https://huseyinkaplan.dev/insights/recommendations-in-the-stores-own-design/ Tue, 06 Oct 2026 09:00:00 GMT Brands said our recommendation widget didn't look like their site. So the engine copies their product card and fills it with ours. JavaScript E-commerce Frontend Architecture https://huseyinkaplan.dev/insights/search-overlay-on-271-storefronts/ https://huseyinkaplan.dev/insights/search-overlay-on-271-storefronts/ Tue, 06 Oct 2026 09:00:00 GMT Shipping a search overlay into 271 stores: rolling back @layer, race guards, Turkish folding, client-side typo tolerance and facets, and a debug catalogue. JavaScript Search UX Accessibility https://huseyinkaplan.dev/insights/write-the-math/ https://huseyinkaplan.dev/insights/write-the-math/ Sun, 04 Oct 2026 09:00:00 GMT In ldraw-nova, models write a plan and a Python generator instead of raw coordinates, but nothing checks physics or stability. AI Engineering AI Agents Python https://huseyinkaplan.dev/insights/notes-read-as-orders/ https://huseyinkaplan.dev/insights/notes-read-as-orders/ Sat, 03 Oct 2026 09:00:00 GMT In stillwet's painter chains, Claude read earlier notes as instructions and missing notes failed silently, so label, log and verify agent handoffs. AI Engineering AI Agents Claude AI https://huseyinkaplan.dev/insights/planner-writes-the-bill/ https://huseyinkaplan.dev/insights/planner-writes-the-bill/ Fri, 02 Oct 2026 09:00:00 GMT In Pi 1.0's demo, Opus used a fifth of the tokens yet cost 18x more than GPT 6 Luna, so log cost per model and count cache misses. AI Engineering AI Agents LLMOps https://huseyinkaplan.dev/insights/isolates-to-microvms/ https://huseyinkaplan.dev/insights/isolates-to-microvms/ Thu, 01 Oct 2026 09:00:00 GMT Netlify's heavier Firecracker sandbox won because it removed a network round trip; count hops and track cold start rate before blaming the runtime. Web Performance Serverless Netlify https://huseyinkaplan.dev/insights/prefill-pays-the-wait/ https://huseyinkaplan.dev/insights/prefill-pays-the-wait/ Thu, 01 Oct 2026 09:00:00 GMT Magnitude's 2x speedup is decode, but at 64K context an agent turn is mostly prefill, so the whole turn gets only about 12% faster. AI Engineering Local LLM LLMOps https://huseyinkaplan.dev/insights/warn-vs-stop/ https://huseyinkaplan.dev/insights/warn-vs-stop/ Thu, 01 Oct 2026 09:00:00 GMT Claude Code mods see every event, but a guard matching command text misses $(...), aliases and scripts; hard blocks belong in permission rules. Claude Code AI Engineering TypeScript https://huseyinkaplan.dev/insights/access-and-memory/ https://huseyinkaplan.dev/insights/access-and-memory/ Wed, 30 Sep 2026 09:00:00 GMT Disconnecting an app from an OpenAI Dots agent stops new reads, but pulled-in context stays, so revoking access and forgetting need separate steps. AI Engineering OpenAI AI Agents https://huseyinkaplan.dev/insights/tokens-move-first/ https://huseyinkaplan.dev/insights/tokens-move-first/ Wed, 30 Sep 2026 09:00:00 GMT livenerf's validation found accuracy noise bigger than the real change, while output token counts clearly showed effort shifts. AI Engineering LLM Evals Claude Code https://huseyinkaplan.dev/insights/reasoning-is-a-budget/ https://huseyinkaplan.dev/insights/reasoning-is-a-budget/ Tue, 29 Sep 2026 09:00:00 GMT Reasoning made Jeeves five points more accurate but pushed p90 latency to 17 s; reasoning only below 0.9 confidence keeps most of the gain. AI Engineering Machine Learning Open Source https://huseyinkaplan.dev/insights/same-price-new-contract/ https://huseyinkaplan.dev/insights/same-price-new-contract/ Tue, 29 Sep 2026 09:00:00 GMT Sonnet 5.5 keeps Sonnet 5 pricing but rejects forced tool_choice and disabled thinking, so check your requests before swapping the model ID. AI Engineering Anthropic TypeScript https://huseyinkaplan.dev/insights/app-lists-the-moves/ https://huseyinkaplan.dev/insights/app-lists-the-moves/ Mon, 28 Sep 2026 09:00:00 GMT taiga-s1 builds FreeCAD parts at about 1 ms per decision because the app lists valid commands each step; check your app's interface first. AI Engineering AI Agents Machine Learning https://huseyinkaplan.dev/insights/sync-is-a-test/ https://huseyinkaplan.dev/insights/sync-is-a-test/ Mon, 28 Sep 2026 09:00:00 GMT Claude Code built a 33-second launch film overnight; the repo muxes audio with ffmpeg and fails the build if sync drifts past 1 ms. AI Engineering Claude Code Remotion https://huseyinkaplan.dev/insights/alert-pages-a-person/ https://huseyinkaplan.dev/insights/alert-pages-a-person/ Sun, 27 Sep 2026 09:00:00 GMT An OpenAI research agent reached a public chatbot through DNS despite a proxy; the alert fired fast, but stopping the run took 2.5 hours. AI Engineering Agent Security DevOps https://huseyinkaplan.dev/insights/missing-ampersand/ https://huseyinkaplan.dev/insights/missing-ampersand/ Sun, 27 Sep 2026 09:00:00 GMT In llama.cpp prompt lookup drafting, reading maps by reference gave 4.5x to 25x, while a flat hash map added only up to 13%. Profile for copies first. AI Engineering C++ Local AI https://huseyinkaplan.dev/insights/agents-need-rails/ https://huseyinkaplan.dev/insights/agents-need-rails/ Sat, 26 Sep 2026 09:00:00 GMT GitHub halved server render time moving Primer to CSS Modules; agents cleared the last 900 sx props only because shims, flags and snapshots existed. ReactJS Web Performance AI Engineering https://huseyinkaplan.dev/insights/widget-without-backend/ https://huseyinkaplan.dev/insights/widget-without-backend/ Sat, 26 Sep 2026 09:00:00 GMT Turnstile tokens can be forged, so your backend must call Siteverify; Cloudflare now flags widgets that skip it with Fix with Spin. Web Security AI Engineering Cloudflare https://huseyinkaplan.dev/insights/comments-break-virtualization/ https://huseyinkaplan.dev/insights/comments-break-virtualization/ Fri, 25 Sep 2026 09:00:00 GMT GitHub's Copilot app PR view keeps exact code row heights and measures review comments in one batched pass near the viewport, never mid-scroll. ReactJS Web Performance Frontend Engineering https://huseyinkaplan.dev/insights/token-diet/ https://huseyinkaplan.dev/insights/token-diet/ Fri, 25 Sep 2026 09:00:00 GMT Most of Cursor's agent spend sits in growing context, not the cached system prompt; on-demand tools and cache breakpoints moved the bill. AI Engineering Cursor Developer Tools https://huseyinkaplan.dev/insights/count-dont-time/ https://huseyinkaplan.dev/insights/count-dont-time/ Thu, 24 Sep 2026 09:00:00 GMT Anthropic made claude.ai about 3x faster and protected the wins by failing CI on deterministic counts instead of noisy wall-clock milliseconds. ReactJS Web Performance AI Engineering https://huseyinkaplan.dev/insights/latency-cheap-crowds-not/ https://huseyinkaplan.dev/insights/latency-cheap-crowds-not/ Thu, 24 Sep 2026 09:00:00 GMT Nemotron 3 Diarization loses almost no accuracy at low latency, but its error roughly triples past four speakers, so test on your own audio. AI Engineering Speech AI Open Source https://huseyinkaplan.dev/insights/agents-bill-for-waiting/ https://huseyinkaplan.dev/insights/agents-bill-for-waiting/ Wed, 23 Sep 2026 09:00:00 GMT DigitalOcean Managed Agents pause microVM billing while sessions sit idle; check idle time, secrets, resume behavior and quotas before moving agents. AI Agents AI Engineering DevOps https://huseyinkaplan.dev/insights/price-war-cached-tokens/ https://huseyinkaplan.dev/insights/price-war-cached-tokens/ Wed, 23 Sep 2026 09:00:00 GMT Opus 5.5 cut cache reads 60% and GPT-6 gives 90% off cached input, so agent costs now hinge on a stable prompt prefix. AI Engineering Anthropic OpenAI https://huseyinkaplan.dev/insights/knowledge-is-free-now-focus-is-still-expensive/ https://huseyinkaplan.dev/insights/knowledge-is-free-now-focus-is-still-expensive/ Wed, 27 May 2026 09:00:00 GMT The internet and AI made knowledge free for everyone, but growth still depends on the scarce part: attention, focus and the discipline to apply. Learning Self Improvement Productivity Focus https://huseyinkaplan.dev/insights/the-ai-api-key-leak-pattern-nobody-wants-to-talk-about/ https://huseyinkaplan.dev/insights/the-ai-api-key-leak-pattern-nobody-wants-to-talk-about/ Mon, 18 May 2026 09:00:00 GMT Why AI API key leaks are spiking in 2026: Gemini changed what public Google keys can do, NEXT_PUBLIC_ ships secrets, and the fix is a server route. Web Security API Next.js AI Engineering https://huseyinkaplan.dev/insights/software-engineering-isnt-dying-it-s-evolving-from-vibe-coding-to-agentic-engineering/ https://huseyinkaplan.dev/insights/software-engineering-isnt-dying-it-s-evolving-from-vibe-coding-to-agentic-engineering/ Mon, 16 Feb 2026 09:00:00 GMT From an 1878 telephone misjudgment to AI agents today: why software engineering is evolving from vibe coding into disciplined agentic engineering. Software Engineering Vibe Coding AI Agentic Engineering https://huseyinkaplan.dev/insights/agent-ready-repo-structure-2026/ https://huseyinkaplan.dev/insights/agent-ready-repo-structure-2026/ Sun, 01 Feb 2026 09:00:00 GMT AI agents fail because of repo ambiguity, not model quality. Here is how AGENTS.md and a clear repo layout make your codebase agent-ready. Developer Tools Artificial Intelligence Software Engineering Productivity https://huseyinkaplan.dev/insights/why-cs50-has-a-1-completion-rate-and-how-i-finished-twice/ https://huseyinkaplan.dev/insights/why-cs50-has-a-1-completion-rate-and-how-i-finished-twice/ Mon, 05 Jan 2026 09:00:00 GMT Fewer than 1% of online learners finish Harvard’s CS50. Why most quit, and the habits that got me through both CS50x and CS50 Web. CS50 Harvard Learning Programming