I recently switched from a standard GKE cluster where I had to manage nodes to an autopilot one where Google does it for me. I must say the switch was easy to do (despite an interruption of our services) and greatly simplified the management of the cluster.
Here are some security tips to check for backend services. It's mostly meant so that I can have a check list. So I don't develop them much but provide extra links where necessary. I also probably expand this list as time goes one and I learn more about this subject …
At work in a PHP application, we rely on libsodium to erase a password from $_POST. It may sound like a good idea: once the password is not in memory any more, it can't leak. But the question is: is it really erased from memory? That's the question will answer …