When API requests are made one-after-the-other they'll quickly hit rate limits and when that happens:
If you provide an API client that doesn't include rate limiting, you don't really have an API client. You've got an exception generator with a remote timer.
— Richard Schneeman Stay Inside (@schneems) June 12, 2019
That tweet spawned a discussion that generated a quest to add rate throttling logic to the platform-api gem that Heroku maintains for talking to its API in Ruby.
If the term "rate throttling" is new to you, read Rate limiting, rate throttling, and how they work together
The Heroku API uses Genetic Cell Rate Algorithm (GCRA) as described by...