The React Compiler is stable and built into Next.js 16, but it is still opt-in. Here is what it does, when I would turn it on as a solo dev, and where I still write useMemo by hand.
I upgraded this site to Next.js 16 — Turbopack builds, Promise-shaped params, and a partial-rendering behavior change that quietly turned one of my security assumptions false. Here's the real upgrade: what broke, what was a non-event, which headline features I deliberately didn't adopt, and the habit that caught the subtle stuff.
