Is there any tooling or recommended way to find dead code?

Doesn’t the compiler warn you about unused functions? Have you looked into it?

As far as i know, dialyzer — OTP 29.0.2 (dialyzer 6.0.1) does that.

Dialyzer is a static analysis tool that identifies software discrepancies, such as definite type errors, code that has become dead or unreachable because of programming error, and unnecessary tests, in single Erlang modules or entire (sets of) applications.

Seems like exactly what you need.

The compiler gives you a warning for unreachable functions. That means private functions which are not called in the module where these are defined are throwing such warnings. But public functions that are never called anywhere are not checked by the compiler.

Exactly I’m trying to figure out a way to check for unused public functions

I think @hauleth can say something about the state of :mix_unused. Or he will be except a PR from you, if you need some changes in the lib.

I am (very) slowly working on that one to work with compiler tracer. I can push my branch (I thought it is pushed) where I am trying to implement such and if you have any PR then it will be more than welcome.

That would be awesome, more than happy to help if I can.

You might also be able to use Erlang’s Xref in a Mix Task. It has options:

locals_not_used(*)
    Returns a list of local functions that have not been locally used.
exports_not_used
    Returns a list of exported functions that have not been externally used. Note that in modules mode, M:behaviour_info/1 is never reported as unused. 

This will return a lot of false positives due to macros and other autogenerated functions in Elixir.

Makes sense, I’ve only used it in Erlang projects.