Citizens report double charges on a fee API. Logs show the payment handler processing the same retried request twice without an idempotency check. What is the most likely code-level root cause to fix?
Select an answer to reveal the explanation.
Short Explanation
Retries are the post office ringing the doorbell twice—if your fee handler does not recognize the same ticket, it charges twice. Idempotency is the "already stamped" mark; missing it is a code bug, not a log-retention tax.
Full Explanation
Debugging application defects includes identifying logic errors such as missing idempotency keys or deduplication when clients or middleware retry. Observability retention, tracing sampling, and custom domains do not by themselves cause duplicate business side effects. Fixing the handler to treat duplicate requests safely addresses the incorrect behavior.