If we're talking about implementations in various languages, I might as well link to my capped backoff with jitter implementation for python.
https://github.com/ekimekim/pylibs/blob/master/libs/backoff....
(apologies for the long link, I keep all my one-file python libs in a single git repo for sanity. I think i've uploaded this one to pypi, where it's available under the name "backoff")
Hi Mike!
Thought you might be interested in my Elixir impl, though not as featureful: https://github.com/rickhull/backoff/blob/master/lib/backoff....
Example usage: https://github.com/rickhull/backoff/blob/master/examples/dem...
It's here if anyone's interested it https://github.com/Diggs/go-backoff