Avoiding Kubernetes Pod Topology Spread Constraint Pitfalls

The Wise Cloud Platform squad uses Pod Topology Spread Constraints to ensure services on Kubernetes clusters in AWS are resilient without incurring significant costs. Misconfigured constraints can lead to unintended Pod skew, particularly during deployments, reducing system resilience in case of Availability Zone failure. They implemented a mutating admission webhook that adds unique labels to distinguish between old and new ReplicaSet Pods, improving proper Pod distribution across Availability Zones.