Direct Call vs Queue

Posted Aug 15, 2026 · 1 view

A direct call keeps the caller's line lit: nothing proceeds until the work returns. Simple to write and simple to debug — and the caller's response time is the slow thing's response time, plus whatever the slow thing does when it fails.

A queue puts a buffer between them. The caller hands the work over and is free immediately; a worker drains the queue at its own rate. The caller stays fast, a downstream outage becomes a backlog rather than an error — and you have accepted that the work is not done when the response is sent.

The animation adds one node and changes the timing. Both channels carry the same point.