Fintech App Landing Page Design & Integration

Hi,
I’m launching a fintech app and need a landing page with backend integration. Here’s what I’m looking for:
Frontend:
Clean landing page for user registration
Fields: Name, Email, Phone, Referral Code(if any), City, State(Dropdown), after registration show personalised referral code which can be shared also displaying if 3 people use this for sign-up then get 7 days free extension
Responsive design (mobile-first)
Backend:
Firebase integration (Firestore + Cloud Functions)
Store user data securely
Track referral codes and count how many users used each code
If a referral code is used by 3+ people, trigger:
Email notification to the referrer
WhatsApp message via API (Twilio or Interakt)
Tracking:
Capture UTM parameters or referral link source (influencer, ad, friend)
Store source info with each registration
Other:
Auto-response email and WhatsApp to new registrants
Admin dashboard to view referral counts and sources
Let me know your estimated timeline and cost for this setup. Happy to jump on a call if needed.
Thanks