What is a Long-Running Workflow?

Unlike a simple request-response function, a long-running workflow has to survive interruption: the process executing it might restart, the server might redeploy, or the workflow might sit idle for days waiting on a signature, and the system needs to resume exactly where it left off rather than losing state or restarting from scratch. This durability requirement is why long-running workflows are typically implemented with an explicit state machine or a durable-execution framework that checkpoints progress after every step, rather than as an in-memory function call that dies if the process does. Designing a long-running workflow well means treating every external wait as a first-class state rather than a blocking call — the workflow engine records "waiting for approval" as a durable state and resumes on the approval event, however long that takes, instead of holding open a thread or connection. Observability matters more here than in short-lived automation, since a workflow stuck for three days needs to be easy to inspect and diagnose, not a black box someone eventually notices has stalled.