Generally something like Postgres or MySQL would have been a better choice in these cases. You can migrate those, as well as handle growth through sharding or clustering, and more easily adapt to changing business or market requirements.

You'll need to recruit differently to build that way, though. Have someone that knows a bit of nginx and Linux, someone able to stitch together a bit of auth, things like that.

Languages with explicit types are also preferable, as a prospective buyer you'd want to have your people become somewhat efficient fast when they start working with the system. If obvious type constraints you kind of have a guarantee that IDE tooling will help with this, whereas Python, Ruby, JavaScript can be rather inscrutable at first glance.

Now, I have a financial interest in these things, it helps me if a system is well built and somewhat easy to evaluate, change and sell, so I have a bias. But in practice it seems that the basic setup of auth, storage and initial business logic takes very little time compared to the time it takes to flesh out the entire system needed to start making a profit, and since most (IT-)companies fail within three to five years it's probably a good bet to try and make the software you build be reusable and/or resellable.