What actually breaks in React and Next.js apps once real users arrive, and how to find the cause rather than the symptom.
Cannot set headers after they are sent to the client. Why it only crashes in production, how to find the handler responsible, and the five code shapes that cause it.
The mismatch that never reproduces locally and appears for a fraction of real users. Why concurrency and caching cause it, and how to find a bug you cannot trigger on demand.
Memory climbs until the container is OOM-killed, and restarting hides it. Five leak sources specific to SSR, how to prove which one you have, and the fix for each.
Text content did not match server-rendered HTML. Five real causes, how to tell them apart, and the code that fixes each one.