Internal tools tend to rot the moment they leave the founding team. We rebuilt our admin from scratch around three principles: every action should be auditable, nothing should require a tribal-knowledge runbook, and there should be exactly one button that resolves the on-call page.
Most database migrations fail not because the SQL is wrong but because nobody tested them against a realistic dataset. We share the rollout checklist we use for every schema change, including the awkward question of when to lock a table and when to live with the inconsistency.
After two years of running a custom message broker we finally pulled the plug and migrated everything to NATS JetStream. The migration took six weeks of careful planning, three weekends of late-night cutovers and one production incident that we are still apologising for.
Every team eventually discovers the joy of shipping behind a flag. Fewer teams discover the misery of cleaning up flags two years later when the original author has long since left the company. A short rant and a longer guide.
There is no faster way to grow as an engineer than spending an evening with a debugger and a project you depend on every day. Here are the libraries that taught us the most and the exact commits worth bookmarking.