https://medium.com/@blackode/how-to-perform-hot-code-swapping-using-distillery-2-a-live-demo-genserver-state-update-53d8344d9147

This article will guide you to perform hot code swapping in Elixir using the Elixir package distillery-2.0 (at the moment of writing this article).

A live demo on updating GenServer state will stand out as a good example.