[the__alchemist]

Rust. Adequate for fun little projects on the side; I find the extra setup time pays itself off in bug prevention and diagnosis quickly, even on small projects. I feel confident my Rust code will have few runtime errors, mutations are predictable etc, while I know my Python code is a minefield, even with precautions like typing. Overall reasons I prefer Rust as a default over Python for most projects:

  - Better (best IMO) official tools
  - Catch many error types at compile time
  - Predictable mutation/pass-by-value vs ref
  - No speed limits
  - Easy to distribute (compared to Python)

All the downsides you've heard about rust are probably true. But when you weigh it as a whole and look at the downsides of other tools, IMO rust rises to the top for many uses.

Kotlin is IMO kind of a mess; too many Javas complications. I may be biased by only having used it for Android.

Important caveat: You mentioned you focus on backends. I can't recommend rust for that due to the immature ecosystem; if you are looking for something like Flask, it is fine. If you want a Django/Rails/Laravel analog, there is nothing that exists on that tier. I recommended it because you're looking for something more general.