This is mrsk: https://github.com/mrsked/mrsk

It is described as "Capistrano for containers"

(This is DHH/37signals so we are in the ruby world)

Mrsk is written in ruby and it is hard to type because autocorrect will change it to the name of a certain billionaire

The actual story is here: https://world.hey.com/dhh/introducing-mrsk-9330a267