You can use Bunnyshell Ephemeral environments for this (bunnyshell.com). - The Postgres instances will be deployed in Kubernetes (bring your own infra if you want), - you can configure seeding, - and also you can run any other containers next to Postgres (for example E2E tests). - You can trigger the process manually or automatically (PR, GH actions, cli tool, API, etc).

For example, the ArgoCD project uses Bunnyshell to create ephemeral envs on each PR. https://github.com/argoproj/argo-cd/pull/18851

Disclaimer: I work for Bunnyshell