Bubble.io Developer for Marketplace Backend

LOOKING FOR A BUBBLE.IO EXPERT TO FINALIZE BACKEND LOGIC & STRIPE FOR A TWO-SIDED MARKETPLACE We are a startup team building a mobile-optimized marketplace application on Bubble.io. We have already fully designed the UI layouts, created the pages, and set up the basic navigation. We need an experienced developer strictly to build the backend logic, database connections, and API integrations. What we need YOU to build (Strictly Backend & Logic): 1. Stripe Connect (Express) Integration: * Set up automated split payments. The platform fee logic must be: 20% from the vendor's price + a flat 0.30€ fee charged from the customer per transaction. * Connect the secure Stripe Onboarding flow to our vendor dashboard so local businesses can link their bank accounts. 2. GPS & Location-Based Map: * Detect the user’s live location via the mobile browser. * Connect a map plugin (Google Maps or Mapbox) to display available database entries dynamically based on the user's distance. 3. Booking Logic & Double-Booking Prevention: * Create database logic for slots/availability. Once a slot is fully booked (e.g., 1/1 places taken), it must instantly vanish from the map and live listings. * Implement strict database locking to prevent two users from buying the exact same item at the exact same split-second. 4. Digital Ticket & Redemption Workflow: * Build an active digital ticket system in the Customer Dashboard upon successful purchase. * Create a secure "Mark as redeemed" workflow/button for the user/vendor to tap, moving the ticket automatically to "past purchases". 5. Auth Fixes, Forgot Password & Language Logic: * FIX CURRENT AUTH BUG: We have an issue where logged-in sessions overlap or log users out incorrectly. Need to secure session states and page redirects based on user roles. * Set up a secure "Forgot Password" workflow using an email delivery tool (like SendGrid/Postmark). * Connect our visual FI | EN header buttons to Bubble's native multi-language system so the app language switches dynamically. (We provide all translations). 6. Security & Performance Optimization: * Set up proper Privacy Rules so vendors can only see their own dashboard data and customers can only access their own receipts. * Optimize all database workflows for Workload Units (WU) efficiency, as we plan to scale past 10,000+ users quickly. Please apply with your fixed-price estimate or hourly rate, and share examples of previous Bubble marketplace apps you have built (specifically involving Stripe Connect or maps).