Outbound email delivery experienced delays of up to 15 minutes due to a queue backlog in the SMTP relay. The issue was identified and resolved by scaling the relay workers.

Build times were elevated due to a cache invalidation issue in the runner pool. Builds continued to succeed but took 3-4x longer than usual. Cache was rebuilt and runners recycled.

Read replicas fell behind the primary by up to 30 seconds during a large batch migration. Read-heavy queries were temporarily routed to the primary. Replication caught up after the migration completed.

P95 latency increased to ~800ms (from typical ~120ms) due to a misconfigured rate limiter. The configuration was rolled back and latency returned to normal.

Planned maintenance window for a major database schema migration. All services were gracefully drained and restored. No data loss occurred and the migration completed within the window.