PostgreSQL Can Replace Kafka for Job Queues Using FOR UPDATE SKIP LOCKED

A developer built a job queuing system using PostgreSQL instead of dedicated message brokers like Kafka or RabbitMQ, avoiding the overhead of additional infrastructure. The key challenge with database-backed queues is preventing multiple workers from processing the same job simultaneously, which could cause issues like duplicate payments. PostgreSQL's FOR UPDATE SKIP LOCKED clause solves this by letting workers lock individual rows and skip already-locked ones, ensuring each job is claimed by exactly one worker. In a test with 100 jobs distributed across three workers, every job was processed exactly once with zero duplicates. The approach also inherits PostgreSQL's built-in durability, meaning jobs persist through crashes without special configuration.