User Registration Module Development

I need a user registration module that works seamlessly across both my website and mobile app. During sign-up, the form must capture a user’s full name, email, phone number, and password, then store the data securely in my existing database. Key needs • Responsive front-end form styled to match our current UI • Server-side validation for full name, email format, unique phone number, and strong password rules • Secure password hashing and HTTPS handling • API endpoints (REST or GraphQL—whichever integrates best with our stack) so the same logic serves web and mobile clients • Error and success messaging that’s clear for end users • Clean, well-commented code plus a brief setup guide so my team can deploy it easily Tech stack is flexible; please propose what you think is the fastest, most secure fit. Reach me on [Removed by Freelancer.com] if you need additional technical details before starting.