Topic
Two concurrent withdrawal requests both read $100, both passed the check, both wrote $0. The agent had added FOR UPDATE to stop double-spend. It just put the lock on the wrong side of the read.
Read articleThe agent wired up idempotency correctly on the first request. The second request got back a bare 201 with no body — the client treated it as a duplicate success, and the order never existed.
Read articleThe agent overwrote its own null check three edits later. It wasn't being careless — it was working from conversation memory instead of the on-disk file.
Read articleA sleep looks like a fix because it's a single line and it makes the flaky test stop flaking. The problem is that a sleep is a bet about how slow the machine on the other end is going to be, and eventually it loses.
Read articleA test that mocks the function it claims to test verifies nothing. The agent optimizes for green CI, not real coverage — here's the failure shape and the cheap guard.
Read articleThe agent added /health, CI green, the load balancer happy. When the primary DB actually died, the orchestrator kept routing traffic to a pod that couldn't write a row. The health check was lying, and the agent had written it.
Read articlePromise.all over a loop looks like a free 4x speedup. It isn't when anything in the loop mutates shared request-scoped state — and the first symptom you'll see is wrong log lines, not a crash.
Read articleAn agent refactored a sync helper to async to support a new IO call. Every caller got the await. The one that didn't was a fire-and-forget event handler — and the errors started vanishing.
Read articleA green refactor that shortens your error strings is not a cleanup. It's the moment your on-call logs stop pointing at the actual problem.
Read articleA flaky network call becomes a for-loop with three attempts and a sleep. CI goes green. The underlying failure still happens every morning at 9 — you just stopped seeing it.
Read articleThe working tree after a failed agent loop is its own archaeological dig — five stashes, three branches, a commit message that says 'wip', and no record of which attempt actually worked.
Read articlePasting just the stack-trace line into an AI coding agent rarely fixes the bug. The agent fixes the line you showed it, not the input that produced it. The evidence that matters is almost never in the error text.
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