At the origin there was a monolith. Behind a successful startup often lies a single technology application (Java, Rails, etc.) that grows until it hardly scales with the number of customers and likewise its development process as developers increase. A consolidated strategy on the back-end is to progressively slice the monolith into micro-services. A dual solution on the front-end is to gradually extract HTML, CSS and JavaScript code into a Single Page Application, applying some techniques like the ones I've been maturing during my experience in Workshare.