export ERL_AFLAGS="-kernel shell_history enabled"
Found that this was a really helpful discussion on better splitting up your project structure.
I'm a huge fan of looking at multiple sources to help solidify my foundtaional knowledge. I've heard good things about this book. I've started reading chapter 5 to make sure I understand GenServer and OTP a little bit more.
Full fledged library for generating xlsx files for reports if you need to.