Mobile and/or Web App Developer OR UI Designer with Development Background Consultation

I'm a UX/UI designer who's looking to either to talk with an experienced UX/UI designer with a development background, or an experienced mobile and/or web app developer who has worked with UX designers to implement a design system for an existing product. The call would be no more than an hour, perhaps a lot less than that if all my questions get answered. The problem: I work for a client who has two products that people use regularly, but there are a lot of design inconsistencies across the products. There has never been a design system in place, but I'd like to convince the client to implement one. I've created design tokens and assigned various variables to said tokens in Figma. I just don't know if the next steps I have in mind for implementing the design system are the correct ones. I'd just like to talk with somebody more experienced than I in this area to work this out. In your application, please provide any evidence of any projects you've worked on where you've worked with UX designers to implement a design system for products that are already shipped.