I wonder what triggered this work at WhatsApp. Are bugs in the ErlangVM frequent enough to motivate the effort? Was it a side-project that was then allowed/founded by the company afterwards? Do WhatsApp have a dedicated team focused on improving the Erlang ecosystem?
erlfuzz is intended to make it safer for us (and others) to hack on the compiler and VM by catching early any bugs that might be introduced. That it also found a bunch of bugs that had been hidden for years is a very nice bonus and validates the approach.
Other recent projects open sourced by my team: - a massive speedup of a common static analyzer for Erlang (https://github.com/erlang/otp/pull/5997) - a type checker for Erlang (https://github.com/WhatsApp/eqwalizer/) - an automated code formatter for Erlang (https://github.com/WhatsApp/erlfmt) - a grammar to easily parse Erlang (https://github.com/WhatsApp/tree-sitter-erlang/)
I do not know their status as of today.