Code optimization hints

hello

I’m newbie of Elixir/Phoenix |> a magnifique toolchain and framework

can I ask where to learn optimization techniques for a 24hx365d up work service?

example:
tail recursion technique
release mode optimization flags
JIT asm?
hype?
DB pooling
scheduler settings for scalability
use compiled native code NIF functions inside BEAM?

please can somebody provide info about reliability / release / config?

thank you
kind regards
Roberto Della Pasqua

The OTP docs include a good reference - the best place to start is with profiling