Hi @mgibowski ,
thanks for the kind words! 
Your concern is definitely understandable, but term_to_binary should not brake backward compatibility. The issue you linked was with a OTP release candidate, and was fixed before the final release. If term_to_binary would break backward compatibility, a lot of other things beyond CubDB would break.
Ultimately, the serialization format provided by term_to_binary is the most solid, low cost, and probably future proof serialization strategy available in Elixir/Erlang. I honestly feel that a custom serialization mechanism would introduce more possibilities for bugs and troubles than leveraging on the battle-tested default Erlang term serialization.
