There is an erlang library for load regulation that I have used in the past.

https://github.com/uwiger/jobs

At the simplest case you can start a job queue which will only allow a specific amount of requests per second. It doesn’t use any external dependencies.

At its simplest:

> jobs.add_queue(:myqueue, [{:standard_rate, 10}])
> jobs.run(:myqueue, fn -> :httpc.request('https://www.forum.elixirforum.com') end)

Runs the jobs at a rate of 10 per second at most

I actually wrote a blog post about this exact problem and go through the process of implementing token bucket and leaky bucket rate limiters using a simple GenServer and a Task.Supervisor: Easy and Robust Rate Limiting in Elixir-Alex Koutmos | Engineering Blog

I’d imagine that you want to persist your queue in the case that the application goes down. You can add that in pretty easily to the code snippets I walk through by implementing the terminate/2 callback.

Hope that helps!