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 team I worked with had a billing service. Every successful checkout fired one final write: an audit-log row, async, after the HTTP response had already gone out. The handler did the right shape: spawn a goroutine, pass the request context, write the audit row. Then they turned on aggressive client-side cancellation. The mobile client tore down the request the instant it had its 200, because mobile networks. The HTTP server cancelled the request context the moment the client hung up. The goroutine inherited that cancellation and the audit-log write returned context.Canceled before it ever hit the database. The audit log started missing rows. Nobody noticed for two weeks because the rows that were there looked normal.…