@ColibriMedia If you plan on working with a Agency/Contractor I would recommend creating an MVP (Minimum Viable Product) or basic model of how the site will function within Excel, list out all requirements, and specific features exactly how you want them completed by your contractor/agency, this is called a Spec and will help the contractor get up to speed at which point they can help you fine tune the spec/requirements.
The contractor you hire can design the entire site directly within the Webflow Designer, making sure the UX matches the functionality and specs you’ve outlined. After the front-end design is complete and you’ve finalized it in Webflow, you will have a front-end MVP of the Web App. Export the front-end code from Webflow straight out of the designer and develop the back-end environment & CMS for the Web Application. I’d recommend building this on a Ruby or Angular back-end.
Once you are finished with these steps you should have a great starting point and hopefully a successful web app which you will continuously improve upon.