Hello Designer friends I am working at a early stage SaaS startup and they have a solution which runs on mobile app and web and I have been designing screens since the last 7 months (It an inventory management app). I think by now it may have more than 90+ screens. I have tried to make the UI across all screens consistent however that was only through the back of my head. So how much time approx would be needed (so I ask time from my boss) to build a design system from scratch?
It's impossible to know as it depends on the number of components, resources, etc that you have to create/update/document. You need to start by doing an audit of what you have and calculate what you need to do.