Hi, I'm planning to develop an app with a serverless backend. Right now my top option seems to be Firebase. But I've heard from some devs that it can get you stuck into its ecosystem and it also tends to be quite expensive once it scales up and you end up being stuck in a situation where you HAVE to muster up the expensive costs because migration out is going to be not worth the effort. Is there a better alternative that I can opt for from the get go? Thoughts on this?