Compiler says OK. Runtime explodes anyway. Here are the 4 patterns where strict null checks isn't enough: assertion functions, untyped libraries, Prisma ORM, and JSON.parse — with real code from a Next.js/Prisma stack.
Jul 23 2026 · 8′ · Tutorials · Next.js · TypeScript
DeepSeek's API is compatible with the OpenAI SDK — that makes the integration almost trivial. The real problem isn't the plumbing. It's deciding whether the model is actually worth it for your use case, without buying the hype or dismissing it out of fashion. Here's the framework.
Jul 22 2026 · 8′ · Tutorials · TypeScript · nextjs
Rate limiting is not a dependency you drop into middleware and call it done. It's an abuse policy. Before you copy that snippet, you need to define what asset you're protecting, what abuse you're expecting, and what a false positive actually costs you.
Jul 07 2026 · 10′ · Tutorials · TypeScript · nextjs
The problem with Next.js caching isn't memorizing the flags. It's deciding how fresh each piece of data actually needs to be. A guide to reading revalidate, dynamic, and no-store as data contracts, not isolated tricks.
Jul 05 2026 · 8′ · Tutorials · React · TypeScript
A healthcheck that only says "the process responds" can hide entire business failures. What Docker HEALTHCHECK actually measures, where people overestimate it, and a decision matrix so you stop promising more than the mechanism can deliver.
Jul 03 2026 · 7′ · Tutorials · docker · devops
Not every signature error is a cryptographic problem. Most of the time the mess is in the format you picked, the certificate that doesn't fit the required profile, or the validation policy the verifier applies. A guide to understanding each layer before you blame the algorithm.
Jul 02 2026 · 9′ · Tutorials · seguridad · pki
Rate limiting isn't an npm dependency — it's an abuse policy. Before copying middleware, you need to define what asset you're protecting, what abuse pattern you expect, and what a false positive costs you. A guide with a decision matrix, real gotchas, and observability for Next.js.
Jun 22 2026 · 9′ · Tutorials · TypeScript · nextjs
Adding an npm dependency isn't just installing code — it's taking on its maintenance, its attack surface, and its transitive deps. Here's the checklist I run before adding any package to a serious TypeScript project.
Jun 22 2026 · 9′ · Tutorials · TypeScript · pnpm
The README on juanchi.dev says "portfolio landing". The code says something else: an editorial system with repo ingestion, quality gate, automatic rewriting, and crons on Railway. The technical story the README doesn't tell.
Jun 22 2026 · 6′ · Next.js · TypeScript
Architecture, real systems, product decisions and technical lessons. Everything reviewed with my own judgment before it ships.
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