Notes on building for the web — React, Next.js, TypeScript, system design & performance.
The WebSocket demo works in five minutes. The problems start after: reconnection, authenticating a long-lived connection, events missed while a client was away & what happens when you run more than one server. Notes from building event-driven real-time systems for real users.
Caching is sold as a performance win and paid for in staleness bugs. A look at the actual decision: which reads are worth caching, how to invalidate without lying to users & the cases where adding a cache creates more problems than the latency it removes.
At a handful of screens, copy-paste is fine. At eighty, it's the thing that kills you. A look at the resource abstraction that held a large admin platform together — and the escape hatches that kept it from becoming a straitjacket.
How to make a page composable from configuration — toggle and reorder sections without touching JSX — using a typed registry and the App Router.
After enough pull requests, mentoring & interviewing early-career engineers, the lessons stopped being about syntax. A reflection on what code review actually optimizes for, why the best comments are questions & how reviewing changed the code I write before anyone sees it.
A single app that speaks to two separate services can quietly leak that split into every component. A shared data layer that owns routing, serialization & uploads keeps the UI from ever knowing there's more than one backend.