We originally cached this data with a Redis cluster but we hit scaling issues. The Read States service only exists because Redis had issues.

We use Elixir too and ironically, Redis became our bottleneck as well. What a useless dependency it is when running on BEAM.

Hah, well now I feel like a dufus. Good info!

No worries, we could have mentioned that in the post as part of the service history :)