In September 2025, GitHub experienced three incidents leading to degraded service performance. On September 15, a feature flag error in the global rate limiter resulted in 403 errors for Copilot, which was quickly resolved by reverting the flag. This incident highlighted an undetected edge case in rate limiting logic, prompting enhancements in system resilience and pre-production validation. On September 23 and 24, email deliveries were delayed due to high traffic causing resource contention on email servers; this led to configuration updates to better handle traffic spikes and improved monitoring for early detection. On September 29, a partial degradation in the Copilot API caused erroneous 404 responses due to a misconfiguration from an internal dependency upgrade, which was resolved by rolling back the upgrade and planning improvements in documentation and rollout processes to prevent recurrence.