reliability

A simple fixed-window rate limiter is often enough for endpoints like login, password reset, webhooks, or expensive searches. Use atomic Redis INCR + EXPIRE with a stable key and return remaining quota for UX.

In production, stack traces without context are slow to debug. Raise custom exceptions that include IDs and safe metadata, and log them as JSON. This is the difference between “we think” and “we know”.

When a dependency is failing, you don’t want to keep hammering it. A simple circuit breaker trips after N failures and short-circuits for a cooldown window. It protects your app and your vendor.