Our self-managed cluster pulled images from ECR fine after setup and failed every morning with no basic auth credentials. The imagePullSecret held an ECR token that expires after 12 hours. We switched to the kubelet credential provider so nodes fetch fresh tokens themselves.
Every deploy of one service failed with another operation is in progress after someone cancelled a pipeline mid-upgrade. The release was stuck in pending-upgrade. We recovered with helm rollback, then added CI concurrency, timeouts and atomic upgrades so it cannot recur.
Training jobs that ran fine on a workstation crashed in containers with a bus error in DataLoader workers. Workers pass batches through shared memory, and containers get only 64 MB of /dev/shm by default. A memory-backed emptyDir in Kubernetes and --shm-size in Docker fixed it.
Our storefront BFF pods restarted every few hours with OOMKilled and exit code 137, then fell into CrashLoopBackOff during the holiday peak. A max-old-space-size inherited from the VM days was double the container memory limit. Sizing the heap to the limit and bounding a cache fixed it.
Half our Argo CD applications showed OutOfSync seconds after every successful sync, and auto-sync kept fighting the HPA over replica counts. The live objects had fields set by controllers and webhooks that Git never mentioned. Targeted ignoreDifferences and server-side diff fixed it.