We have a Rails monolith with a couple internal Sinatra services if that counts. To be honest, I love working with Sinatra and Sequel (when using an ORM) vs.

We have a Rails monolith with a couple internal Sinatra services if that counts. To be honest, I love working with Sinatra and Sequel (when using an ORM) vs. working with Rails and ActiveRecord. We provide public apis via. Grape, but that's mounted as an engine inside our monolith vs. deploying our own Grape application on Rack just for operational simplicity.