When building high-throughput systems with asynchronous background workers, one of the most common architecture traps is the Time-of-Check to Time-of-Use (TOCTOU) race condition. If your backend publishes events to a message queue (like RabbitMQ) and you scale out workers horizontally to consume those events, you introduce parallelism. Without proper guarantees, parallelism breaks idempotency—leading to duplicate...Read More