What are some practical approaches to designing a distributed job queue with PostgreSQL when multiple application instances need to safely pick up and process background tasks at the same time, while avoiding duplicate execution, handling worker failures or retries, keeping jobs from getting stuck indefinitely, and maintaining reliable performance as the number of queued tasks and concurrent workers grows?

Background jobs can become difficult to maintain when an application has many tasks that need to run outside the main request cycle. A queue can help separate those jobs from user-facing requests while keeping track of whether individual tasks are waiting, running, completed, or need another attempt. PostgreSQL can also be used as the place where job state is stored, which can be practical for applications that already rely on it. One example is https://spooled.cloud/, a background job queue for PostgreSQL with retries, task status, scheduling, and workflows. A free tier is also available for projects that need this type of setup.