To elaborate on this a "traditional" stack of Phoenix for the web and and Ecto for the DB uses quite a bit of OTP, particularly if websockets are involved (ever

To elaborate on this a "traditional" stack of Phoenix for the web and and Ecto for the DB uses quite a bit of OTP, particularly if websockets are involved (every connection is a GenServer). The thing is, going from Ruby to Elixir involves two learning curves: groking functional programming, and then groking processes. They really do need to be learned in that order since, within any given process, you're just operating in a relatively normal functional world. HTTP requests are very easily envisioned in a simple functional way. You've got request data in, and you're gonna return response data. The interaction you have along the way with OTP based database pools and so forth is as a client, you aren't really having to manage the lifecycle of any of that stuff. In other words to get going with basic web stuff it's more critical to just become familiar with functional programming, and less critical to understand how OTP works. This is totally fine from a learning curve perspective. What's cool about Phoenix channels though is that each user's connection, and each channel that they run is a GenServer. It provides a great opportunity to get some hands on interaction with the concept in a way that naturally fits into with the web application they're building. TL;DR:You can be a client / user of OTP processes without knowing the details of how they work, and that's generally enough for HTTP.