Ecto and EctoSQL covers a lot of ground and its abstractions are interesting if a bit overwhelming sometimes.
Not having a lot of experience with ETS and the like… CubDB has resulted to be super useful, beautiful data store you can rely on, with easy to grasp query capabilities.
Norm is super fun to play with, it is a way to specify the “form” of your data so it can be validated at run-time. I have been learning a lot around “Design by Contract” thanks to it! Seeing the pros and cons compared against the static analysis tools (dialyxir, gradualixir) and methodologies (automated tests) we use on a language like elixir.
Decimal is great but it will probably come bundled with another library, like ex_money which might save you a lot of work if you ever need to handle different currencies. EEx for anything about “templating”.
I would love to play more with:
moebius, as an alternative to Ecto. It seems to have full-text-search query capabilities and document schemas out of the box
drab, I’m currently invested in learning LiveView but would love to check-out what I’m missing by not using this library.
witchcraft, as a bunch of really powerful operators I yet don’t really grasp.
@entone already mentioned a bunch. There’s a really vast ecosystem of “GenServer derivates” when you need anything related to “distribution” or “reliability”.