UI/UX redesign for Windows system to HTML

We have a legacy Windows system that connects to our back-end API. We want to rewrite the front-end in HTML using the same API, with extensions as required.

We are looking for someone who can takes some of the screens we have and design a new UX/UI.

The system is used in e-commerce so UX experience in back-end e-commerce would be good, e.g. processing orders, creating products, listing inventory.