I only recently moved to Rails though. Before that I was full stack TypeScript, which was cool and I still miss the static types, but it’s worth going without them.
Node is great, but I didn't come across any frameworks that rival Django or Rails in terms of maturity, and for a side project with no special requirements in terms of scalability etc., I'm not really interested in piecing together multiple libraries or writing a lot of code myself.
I actually ended up building the back-end twice lol - I was looking for the opportunity to try out GraphQL (overkill really, and it goes against what I said about keeping things simple, but I felt it was a good opportunity to try it) and ended up hitting some big performance issues with Django + Graphene – not sure how much of it was my fault vs. Python's GraphQL being slow, but in the end I rewrote the API in Rails + ruby-graphql in half a day and the performance is 5-10x faster there.
Having had the opportunity to build the same thing in them both, I'd say that Django's ORM is quite a lot better (I prefer the Django way of "update the model and the ORM will work out what migrations you need" vs Rails where you explicitly create migrations) and I prefer the Python language (simpler syntax, Ruby has so many ways to express the same thing); but Rails is probably actually quicker to work with and the quality of the Gems available for common stuff seems better than the Django equivalents.
Ultimately both Rails and Django let you get a lot done with not much code and are pretty similar conceptually – I'm impressed with both!