go

When you need accurate request logs or metrics, you can’t rely on “what you intended to write” — you need what actually got written. Wrapping http.ResponseWriter to capture WriteHeader and count bytes is a simple way to record status codes and respons

Retries alone can make an outage worse: if a dependency is hard failing, retries just add load. A circuit breaker adds a simple state machine: closed (normal), open (fail fast), and half-open (probe). I like gobreaker because it’s small and predictabl

Compressing responses is an easy bandwidth win for JSON APIs, but only when it's done carefully. I check Accept-Encoding for gzip, set Vary: Accept-Encoding so caches behave correctly, and stream output through gzip.Writer so we don't buffer full resp

For internal admin endpoints, I often add a network allowlist in addition to auth. The tricky part is deciding which IP to trust: if you’re behind a proxy, you might need X-Forwarded-For, but only if the proxy is controlled by you. The middleware belo

I often need a fast read path for small datasets (like a list of active plans or an allowlist) that updates periodically. Instead of locking on every read, I store a pointer to an immutable snapshot in atomic.Pointer. Reads are lock-free and safe; ref

When latency matters, I benchmark the smallest interesting unit and watch allocations. In Go, a surprising number of regressions come from accidental heap churn: converting []byte to string, building lots of temporary maps, or using fmt.Sprintf in loo

A lot of handler complexity disappears if you reject bad requests early. I enforce the HTTP method (POST, PUT, etc.) and require Content-Type: application/json before attempting to decode. This prevents confusing errors where clients send form-encoded

When a cache key expires, it’s easy for a burst of requests to stampede the database. I use singleflight.Group to ensure only one goroutine performs the expensive fill per key while others wait for the shared result. This doesn’t replace proper TTLs o

For transactional email, the reliability problem is usually latency and retries, not MIME formatting. I prefer an HTTP email provider because requests are easy to bound with context.WithTimeout and easier to observe than raw SMTP. The code below build

When multiple clients can update the same record, I prefer optimistic locking over heavy row locks. The idea is simple: every row has a version that increments on each update. The update statement includes WHERE id=$1 AND version=$2, so if someone els

In containerized environments, the Go runtime can benefit from knowing the memory budget. With Go 1.19+, debug.SetMemoryLimit lets you set a soft limit so the GC reacts more aggressively before the process gets killed by the OOM killer. I treat this a

Sometimes you want a quick diagnostic without wiring a full metrics stack. expvar exposes variables at /debug/vars in a standard JSON format. I use it for a handful of counters like “requeststotal” and “jobsfailed” when I’m bootstrapping a service or