Writing
Backend and systems engineering explained in plain English, using problems I hit in production.
5 articles
OAuth Is Not “Login.” I Found That Out the Hard Way in Production
OAuth is a permission system, not a login system. Letting an OAuth token and my own JWT share one cookie key logged users out in production.
Why 100% CPU Doesn’t Mean What You Think It Means
Pages were slow and the database sat at 100% CPU, so the database got the blame. A SQL trace showed one COUNT(*) query running roughly 80 to 90 times a second.
Redis Is Single-Threaded… So Why Is It So Fast?
Redis serves 100,000+ requests per second on one command-execution thread. The mechanism is I/O multiplexing, an event loop, and since Redis 6, I/O threads.
The Silent Design Decisions That Make Users Feel Understood: A Mobile UX Guide
73% of users abandon apps within the first week, not because of bugs but because the app “just doesn’t feel right.” These are the UX decisions that made Moodly feel like it gets you.
Localhost: Talking to Yourself in the Digital World
Typing localhost sends your request to your own machine through the loopback address 127.0.0.1, so nothing ever leaves your computer.