When I started with Arya, they had a handful of tools, all stuffed into material design. It wasn't Beautiful or even logical but it worked well enough for Kunal (ceo) to sell pilots and eventually me. Fast forward to today and Arya now runs on seamless, adaptive, and skinable front end that it's customers love.
Step one was to make sense of it all. Much had been thought up and somethings had been testes. My first step was to clean up everything and get it into a master file so that anyone in the company could see how things connected and the impact of each feature.