Full-Stack Developer — Custom Web App (Member Management & Stripe Payments)

Overview I am looking for an experienced full-stack developer to build a custom-coded, mobile-first web application for a sports club. The portal serves two user types — parents and club administrators — and handles class enrolment, Stripe payment processing, member account management, and automated email communications. A detailed functional specification is ready and will be shared in full once an NDA is signed. The Airtable database schema (20 tables) is already fully designed and built. Brevo email templates are done. This is a build-to-spec engagement — not a discovery project. What You Will Build — Responsive web application, mobile-first, accessible via browser URL — Parent portal: account login, class browsing and enrolment, Stripe payments, profile management, messaging centre — Admin dashboard: member management, class and capacity controls, financial reporting, bulk operations, automated communications — Native Stripe integration including payment intents, webhooks, reconciliation, and instalment logic (Pay in 2 / Pay in 3) triggered at admin-configurable thresholds — Automated email workflows via Brevo (templates already designed by client) — Airtable as central database via API (schema already built — 20 tables) — Make.com automation for key workflows — Typeform integration for class request intake — All settings admin-configurable — no hardcoded values anywhere Tech Stack (Fixed — No Substitutions) — Custom code only — no WordPress, no page builders, no low-code platforms — Airtable as database layer (existing schema supplied to successful candidate) — Stripe as the sole payment provider — Brevo for transactional and automated email — Make.com for automation workflows — Typeform Basic for form intake — All data must be stored within EU data centres What Is Already Done — Client Side — Full functional specification (every feature described at sub-component level with acceptance criteria) — Airtable schema — 20 tables, fully designed and built — Brevo email templates — designed and copywritten across all automated comms — Fee calculator prototype in HTML/JS — Make.com and Typeform setup for one workflow already configured — UI mockups for key screens Project Terms — Fixed price only — all-in quote required at proposal stage; no hourly billing — Milestone-based payment — payment released on accepted deliverables, not time spent — All source code committed to client's private GitHub repository at minimum every two working days — Staging environment required throughout the build — Full handover package required on completion: technical documentation, deployment guide, admin user guide, credential inventory — NDA and IP Assignment Agreement required before full specification is shared — standard documents, prepared and ready — Weekly video check-in and written progress updates between calls — Target go-live: September 2026 Ideal Candidate — Mid-to-senior full-stack developer with strong portfolio of custom web application builds — Proven Stripe integration experience in production — webhooks, payment intents, reconciliation, instalment logic — Comfortable working from a detailed specification to agreed acceptance criteria — Experience with Airtable as a database layer via API (desirable but not essential if strong REST API background) — EU-based, available to begin within two to three weeks of contract signing — Strong written and verbal English communication — Portfolio or GitHub showing relevant custom application work Budget €15,500 – €22,500 fixed price. Full specification shared on NDA. Proposals outside this range will not be considered. Please include in your proposal: your relevant experience with Stripe in production, a link to relevant work or GitHub, your location, your availability, and your fixed-price quote for a project of this scope based on what you can see here. Full spec shared immediately on NDA