#Worker
2 articles
Workflow
Always Claim the State Before Sending Anything Out
A "read the state, then send" guard looks safe until a worker gets killed after sending but before writing to the database, and a retry sends the same thing to the customer twice. This article covers the full set of duplicate prevention measures I use, from atomic claims to retry_after and failed() handlers that must never overwrite a successful state.
One Codebase, Two Roles: Hosted Web, Worker at Home
The whole system used to run on one machine behind a home internet connection. When that machine went down, the team could not use anything. I split it into two roles using the same codebase — the web runs on an always-on host, while heavy work stays on the home machine, which pulls jobs itself, with an atomic job-claim table and an 18-step cutover plan with a rollback path.