If your container is stateless then the ongoing process in the old pod just keeps running until it finishes or the pod is terminated, scaling out doesn’t interrupt it but the new pods wont pick up that same process they’ll just take new work. For statefull stuff its more tricky, if the process depends on local state and that pod goes away you can loose progress unless your app is coded to persist state to some external storage like a DB or volume. HPA itself doesnt migrate running tasks between pods so you gotta handle that logic in the app or job queue.