https://albeltran.com/blog/ Engineering notes and interview prep by Al Andrew Paul Beltran. Published articles only. en-ph https://albeltran.com/blog/react-compiler-is-a-purity-contract/ https://albeltran.com/blog/react-compiler-is-a-purity-contract/ Thu, 17 Sep 2026 00:00:00 GMT React Compiler only pays off if render stays pure. Memo soup is not the same contract. Here is what I change in components before I trust automatic memoization. https://albeltran.com/blog/nextjs-use-cache-is-a-commit/ https://albeltran.com/blog/nextjs-use-cache-is-a-commit/ Thu, 17 Sep 2026 00:00:00 GMT Cache Components in Next.js look like a performance flag. They are a freshness contract: what is cached, who invalidates it, and what the user is allowed to see stale. https://albeltran.com/interviews/typescript-interview-questions/ https://albeltran.com/interviews/typescript-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT Types at boundaries, narrowing, generics, and the questions that separate autocomplete from design. https://albeltran.com/blog/typescript-api-contracts/ https://albeltran.com/blog/typescript-api-contracts/ Sat, 05 Sep 2026 00:00:00 GMT Share types across producer and consumer, validate at the edge, and stop trusting JSON because it compiled once. https://albeltran.com/interviews/system-design-interview-questions/ https://albeltran.com/interviews/system-design-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT A small set of design prompts with the tradeoffs interviewers listen for — not a 50-box diagram. https://albeltran.com/interviews/sql-interview-questions/ https://albeltran.com/interviews/sql-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT Joins, indexes, NULL, and transactions — answered the way a production engineer talks about plans. https://albeltran.com/interviews/react-interview-questions/ https://albeltran.com/interviews/react-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT A compact React interview set: hooks, rendering, state, and architecture — with what interviewers are actually scoring. https://albeltran.com/blog/react-hooks-mental-model/ https://albeltran.com/blog/react-hooks-mental-model/ Sat, 05 Sep 2026 00:00:00 GMT Treat hooks as subscriptions to render, not lifecycle methods with new names. The model that prevents stale state and mystery effects. https://albeltran.com/interviews/nodejs-interview-questions/ https://albeltran.com/interviews/nodejs-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT The event loop, errors, streams, and production habits — not a list of module names. https://albeltran.com/blog/lambda-failure-modes/ https://albeltran.com/blog/lambda-failure-modes/ Sat, 05 Sep 2026 00:00:00 GMT Timeouts, retries, partial batch failure, and the handler that is not idempotent. https://albeltran.com/interviews/javascript-interview-questions/ https://albeltran.com/interviews/javascript-interview-questions/ Sat, 05 Sep 2026 00:00:00 GMT Closures, the event loop, equality, and this — explained as runtime behavior, not trivia. https://albeltran.com/blog/aem-author-developer-contract/ https://albeltran.com/blog/aem-author-developer-contract/ Sat, 05 Sep 2026 00:00:00 GMT A component is successful when an author can use it without a Slack thread. Dialogs, names, and defaults are the product. https://albeltran.com/blog/chip-vendor-model-hub/ https://albeltran.com/blog/chip-vendor-model-hub/ Thu, 03 Sep 2026 00:00:00 GMT If the company that sells the chips also owns the default place engineers pull open models, pinning, licensing, and exit plans stop being theoretical. https://albeltran.com/blog/agents-need-monitoring-layers/ https://albeltran.com/blog/agents-need-monitoring-layers/ Tue, 01 Sep 2026 00:00:00 GMT Frontier models are being wrapped in eval gates and misalignment monitors. Most product agents still log prompts and hope. That gap is now the production problem. https://albeltran.com/blog/sqlite-at-the-edge/ https://albeltran.com/blog/sqlite-at-the-edge/ Sat, 22 Aug 2026 00:00:00 GMT D1, Turso, LiteFS, and a decade of Postgres-by-default have teams rediscovering a file database. The win is locality. The bill is replication and migration discipline. https://albeltran.com/blog/rag-demos-die-in-production/ https://albeltran.com/blog/rag-demos-die-in-production/ Wed, 12 Aug 2026 00:00:00 GMT Retrieval-augmented generation looks finished in a notebook. In production it is a search problem, a freshness problem, and an evaluation problem wearing a chat UI. https://albeltran.com/blog/idempotency-keys-are-the-contract/ https://albeltran.com/blog/idempotency-keys-are-the-contract/ Sat, 01 Aug 2026 00:00:00 GMT Retries are not an edge case. If a client can double-submit a payment, a reward, or a provision call, the header that names the attempt is the interface. https://albeltran.com/blog/post-quantum-tls-is-an-ops-problem/ https://albeltran.com/blog/post-quantum-tls-is-an-ops-problem/ Tue, 21 Jul 2026 00:00:00 GMT Hybrid key exchange is landing in browsers and CDNs. The engineering work is inventory, dual-stack certificates, and not breaking the middleboxes you forgot you had. https://albeltran.com/blog/platform-engineering-is-not-a-portal/ https://albeltran.com/blog/platform-engineering-is-not-a-portal/ Thu, 09 Jul 2026 00:00:00 GMT A golden path is paved workflows, paved defaults, and a team that owns the pavement. A catalog of links with a search bar is a bookmark manager. https://albeltran.com/blog/serverless-still-has-a-latency-budget/ https://albeltran.com/blog/serverless-still-has-a-latency-budget/ Sat, 27 Jun 2026 00:00:00 GMT Managed functions removed capacity planning. They did not remove tail latency, cold starts, or the cost of chatty downstreams. You still have a budget. It is just itemized differently. https://albeltran.com/blog/observability-without-slos/ https://albeltran.com/blog/observability-without-slos/ Tue, 16 Jun 2026 00:00:00 GMT Dashboards that cannot tell you whether to wake someone up are decoration. Start from the user promise, then buy traces. https://albeltran.com/blog/typescript-won-the-integration-layer/ https://albeltran.com/blog/typescript-won-the-integration-layer/ Thu, 04 Jun 2026 00:00:00 GMT The interesting TypeScript story is not frontend fashion. It is the language teams use to glue APIs, workers, and infrastructure code that used to be a pile of untyped scripts. https://albeltran.com/blog/css-caught-up-to-layout/ https://albeltran.com/blog/css-caught-up-to-layout/ Sun, 24 May 2026 00:00:00 GMT Container queries, :has(), and nested CSS removed a generation of JavaScript measuring hacks. The remaining work is restraint: not every layout needs a new primitive. https://albeltran.com/blog/feature-flags-beat-long-lived-branches/ https://albeltran.com/blog/feature-flags-beat-long-lived-branches/ Wed, 13 May 2026 00:00:00 GMT A flag in production is a smaller, reversible risk than a branch that only exists on one laptop. Trunk-based delivery is an operations choice, not a Git fashion. https://albeltran.com/blog/supply-chain-security-is-runtime/ https://albeltran.com/blog/supply-chain-security-is-runtime/ Sat, 02 May 2026 00:00:00 GMT xz and a decade of npm incidents taught the same lesson: you run other people's code. Pinning, provenance, and a small dependency graph beat a PDF named policy. https://albeltran.com/blog/spa-hangover-and-server-components/ https://albeltran.com/blog/spa-hangover-and-server-components/ Tue, 21 Apr 2026 00:00:00 GMT Client-rendered apps solved a 2015 shipping problem. They also shipped empty shells and waterfalls. Server Components are a boundary tool, not a rewrite religion. https://albeltran.com/blog/local-first-sync-is-a-product-problem/ https://albeltran.com/blog/local-first-sync-is-a-product-problem/ Sat, 11 Apr 2026 00:00:00 GMT CRDTs and sync engines are impressive. Users still need a story for conflict, offline writes, and what happens when two cashiers sell the last seat. https://albeltran.com/blog/sql-still-compounds/ https://albeltran.com/blog/sql-still-compounds/ Thu, 02 Apr 2026 00:00:00 GMT Models can draft a query. They cannot own the index, the cardinality, or the 2 a.m. plan that scans the wrong partition. Relational literacy is still leverage. https://albeltran.com/blog/rate-limits-are-product-design/ https://albeltran.com/blog/rate-limits-are-product-design/ Thu, 26 Mar 2026 00:00:00 GMT 429s are not just a WAF rule. They encode who gets capacity, what a client should do next, and whether your API is a partner or a trap. https://albeltran.com/blog/wasm-on-the-server/ https://albeltran.com/blog/wasm-on-the-server/ Wed, 18 Mar 2026 00:00:00 GMT WebAssembly in the data center is useful when you need isolation, multi-language plugins, or a portable sandbox. It is not a replacement for a well-run service. https://albeltran.com/blog/event-driven-loyalty/ https://albeltran.com/blog/event-driven-loyalty/ Thu, 12 Mar 2026 00:00:00 GMT How an activation-to-reward pipeline using SQS, SNS, Lambda, and Talon.One keeps fintech loyalty flows decoupled and operable. https://albeltran.com/blog/event-sourcing-without-religion/ https://albeltran.com/blog/event-sourcing-without-religion/ Thu, 26 Feb 2026 00:00:00 GMT An event log is a tool for audit and replay. It is not a requirement for every domain object. Most systems need durable facts and a projection, not a conference architecture. https://albeltran.com/blog/webgpu-browser-as-compute/ https://albeltran.com/blog/webgpu-browser-as-compute/ Wed, 18 Feb 2026 00:00:00 GMT When the tab can run serious GPU work, the architecture question is not 'can we?' It is 'should this run next to the user's passwords, and what is the fallback?' https://albeltran.com/blog/ai-augmented-engineering/ https://albeltran.com/blog/ai-augmented-engineering/ Sun, 18 Jan 2026 00:00:00 GMT How Claude and Cursor can compress design, coding, and review cycles while keeping architecture and production decisions human-owned. https://albeltran.com/blog/aem-reusable-components/ https://albeltran.com/blog/aem-reusable-components/ Tue, 04 Nov 2025 00:00:00 GMT Lessons from enterprise Adobe Experience Manager delivery on making component libraries useful for authors, not just developers. https://albeltran.com/blog/performance-15s-to-2s/ https://albeltran.com/blog/performance-15s-to-2s/ Thu, 21 Aug 2025 00:00:00 GMT A practical account of performance work on a high-availability insurance technology platform: find the critical path, measure, then simplify. https://albeltran.com/blog/serverless-etl-lessons/ https://albeltran.com/blog/serverless-etl-lessons/ Fri, 09 May 2025 00:00:00 GMT What matters when Lambda, S3, and Step Functions process high-volume data under production SLAs.