I’d add make sure you’re learning languages in very different fields. IE, you won’t get much out of learning Ruby after Python (some, but not much). But C or Ha

I’d add make sure you’re learning languages in very different fields. IE, you won’t get much out of learning Ruby after Python (some, but not much). But C or Haskell? Definitely. Also don’t automatically be afraid of old languages. People still write a lot of new things in FORTRAN for instance (really!). And you can make better COBOL jokes if you read it’s wikipedia page at least. Also, languages for describing hardware or FPGAs can be mind bending (Verilog or VHDL), and GPU languages are an excellent thing to have in your toolset whether it’s just for making pretty pictures or doing machine learning. Also learn at least one assembler/bytecode, even if it’s just a vm one. Whatever language you learn make sure it adds something to your toolset you couldn’t do in another language. The whole “10x programmer” thing probably is based on warped ideas for the most part, but I would guess that if you have a colleague that’s ten times more productive than the rest of the team it’s because they understand and can reason about parts of the stack and machine others can’t