Edgecase Engineering
Edgecase Engineering
Software architecture, AI systems, backend engineering, and real-world build notes.
About
Hammed Ajibade
Senior backend / AI systems engineer
Latest posts
Rate limit headers should describe the next safe attempt
A 429 response is more useful when it tells the caller how recovery actually works, not only that a threshold was crossed
How long should an idempotency key live
The retention window is part of the contract, because replay safety ends the moment the original decision record disappears
A manual replay needs the reason that justified it
An operator-triggered replay is safer when the system preserves why the original uncertainty was judged replayable at all
A 202 response needs a receipt trail
Accepted is a queueing answer, not proof that the later work finished, so the system still needs a trackable chain of receipts after the first response
When the error message lies about the failure
A production incident gets slower and riskier when the recorded failure names the wrong boundary
Receipts should outlive the retry budget
A delivery record stays useful only if the acknowledgement evidence survives long enough for replay, support, and audit decisions
Timeouts should keep their doubt
A delivery timeout should preserve uncertainty clearly enough that the next operator does not confuse missing evidence with a confirmed failure
Dead letter queues should keep the reason
A failed delivery is more reviewable when the queue preserves why the handoff stopped, not only the payload that did not move
Replay starts with the original request ID
A safe replay path keeps the first delivery visible, refuses blind retries, and records the second attempt as its own event
Webhook retries need receipts
Reliable delivery starts by recording what the receiver accepted, not by sending the same payload louder
Idempotency comes before retries
Reliable dispatch systems make repeated delivery safe before they make repeated delivery fast
Why AI agents fail in production: state drift, not prompt drift
A practical state-convergence playbook for project-scoped agent systems