Great answers below (test containers for example). However, it’s not always possible. For example: - you use oracle db (takes minutes to start, license, hope

Great answers below (test containers for example). However, it’s not always possible. For example: - you use oracle db (takes minutes to start, license, hope the containers run on ARM fine, etc.) - sometimes an in memory fake is just much faster, and can be an official db on its own for people to try the product - your storage might be only available through a library by a third party provider that is not available locally.