Question

A mobile app backend runs behind a managed API gateway. During a marketing promotion, users report intermittent failures. The application logs show a burst of HTTP 429 responses returned by the gateway itself, while backend service CPU, memory, and latency metrics all remain well within normal ranges. What is the MOST likely root cause?

Accepted Answer

The API gateway's configured rate/throttling limit is being exceeded by the surge in request volume

Answer

The backend instances are overloaded and rejecting new connections

Answer

TLS certificates on the gateway have expired, blocking client requests

Answer

A misconfigured DNS record is directing traffic to the wrong endpoint