I would design your web and mobile app with a full prototype. If needed, create a PRD for every feature in the product brief to help the developer. I have over 5 years of experience designing web apps, mobile apps, landing/marketing pages that span across industries like EduTech, E-Commerce, CyberSec, SAAS, among others. Pls feel free to reach out if you're not sure if u need me. First consult is free.