All you need is Rails (Engines): Compartmentalising your Monolith - YouTube

(Julián Pinzón Eslava) "As much as Rails is all in on Convention over Configuration, there comes a point where there is just so much code, such intricate relationships between classes and such complex business requirements that conventions don’t seem to fit anymore. It seems like the only solution is to abandon the Majestic Monolith and use micro services.However, there is an answer to this. An answer that’s been there for a very long time, right under our noses. One that allows Ruby on Rails developers to keep growing a beautiful, sustainable and scalable Monoliths and ride with them to the sunset.The answer is Rails Engines.Like… Devise or Spree?Not quite. In this talk you’ll learn a whole new perspctive on Rails Engines.