Book: The Complete Guide to Go Programming Also by me: Thinking in Go (2-book series) — Complete Guide to Go Programming + Hexagonal Architecture in Go My project: Hermes IDE | GitHub — an IDE for developers who ship with Claude Code and other AI coding tools Me: xgabriel.com | GitHub A backend team I talked to last quarter had a flaky integration suite that passed locally and failed once a week in CI. The failure was always the same: a Postgres test row that should not exist still existed when a later test queried for it. They added sleeps. They added retries. They added a "skip flaky" tag. The test stayed flaky for four months. The bug was four lines of test setup. A parent test opened a shared transaction, registered t.Cleanup to roll it back, then spawned three sub-tests with t.Parallel() . Sometimes the rollback ran while a parallel child was still mid-INSERT. Race detector said nothing. go test -v said the parent passed. The data said otherwise.…