Full-Stack Developer for Wellness Marketplace

Full-Stack Developer or Team Needed for a Production-Ready Two-Sided Marketplace. Experience with Next.js, Supabase, Stripe, Role-Based Dashboards and Marketplace Workflows Required. I am seeking an experienced full-stack developer or small development team to build a complete, production-ready, two-sided marketplace web application. This posting intentionally provides a high-level overview only. Additional product details, workflow specifications and business rules will be shared with shortlisted candidates after an initial screening and confidentiality agreement. I am not looking for a frontend-only build, no-code prototype, clickable mockup or partial proof of concept. Please estimate the complete application, including frontend development, backend architecture, database design, authentication, payment integrations, marketplace logic, administrative tools, testing and production deployment. High-Level Product Overview The application will connect consumers seeking specialized services with approved service providers. At a high level, the marketplace workflow includes: 1. A consumer submits a structured request. 2. The system identifies and notifies a limited group of qualified providers. 3. Providers submit private, time-limited responses or offers. 4. The consumer compares the available options. 5. The consumer selects a provider and completes a platform-level payment. 6. The platform tracks the resulting booking or transaction status. 7. The consumer may submit a verified review after completion. The platform must be designed to support multiple geographic markets and service categories without requiring a major rebuild. Complete Build Scope The selected developer or team will be responsible for the complete platform, including the following areas. Consumer Application * Responsive, mobile-first consumer experience * Multi-step request or intake flow * Guest submission with account creation later in the process * Save-and-resume functionality * Location-based matching * Structured API endpoint for receiving data from an external intake system * Status tracking and notifications * Side-by-side comparison of provider responses * Provider profile and credential information * Provider selection * One-time payment collection through Stripe * Booking or transaction status management * Consumer-provider messaging * Verified reviews * Account and data-deletion functionality Provider Application * Provider registration and onboarding * Organization and staff account management * Provider profile creation * Services, service areas, availability, pricing information and business details * Credential and verification-document uploads * Administrative review and approval * Mobile-friendly opportunity review and response submission * Private responses that are not visible to competing providers * Time-limited response windows * Opportunity inbox * Active, won and lost opportunity history * Booking or engagement management * Subscription and usage visibility * Reviews and provider responses * Billing history * Notification preferences Please identify separately whether supporting multiple users within each provider organization materially affects cost. Marketplace and Matching Logic * Matching requests with a limited group of eligible providers * Configurable matching and eligibility rules * Administrative control over marketplace rules * Audit trail for important system decisions * Timed response windows * Automated expiration and status changes * Usage or quota tracking * Lifecycle notifications * Reliable state management across the complete marketplace workflow The exact matching rules and commercial logic will be provided to shortlisted candidates. Payments and Subscription Billing Stripe will be used for a combination of: * Provider subscription plans * Different usage allowances by plan * Usage-based or overage charges * Introductory or promotional billing periods * Conditional subscription activation * Plan upgrades and downgrades * Cancellations * Failed-payment handling * Invoices and billing history * One-time consumer payments * Refund processing The platform will not process the underlying payment between the consumer and service provider. Marketplace payouts, escrow and Stripe Connect are not currently part of the scope. Administrative Console The administrative application must support: * Provider approval and verification * User and organization management * Consumer-request management * Marketplace-rule configuration * Usage adjustments or credits * Review moderation * Refund management * Support and dispute workflows * User impersonation for customer support * Platform metrics and funnel reporting * Subscription and usage visibility * Notification-template management where practical Public Website and Content System The build will also include a server-rendered public website and content-management layer. This portion should include: * Core marketing pages * Provider-acquisition pages * Service and location landing pages * About and legal pages * A CMS or developer-friendly content system * Ability for a non-developer to publish and edit long-form content * Reusable page templates * Programmatic landing-page support * Semantic URLs * Sitemap and canonical handling * Page-level metadata * Structured data * Strong technical SEO * Core Web Vitals optimization Content writing, brand identity and logo development are not included. Planned Technology Stack The preferred stack is: * Next.js * React * TypeScript * Supabase * PostgreSQL * Supabase authentication, storage and row-level security * Stripe * Vercel * Cloudflare * PostHog * GitHub * Sentry or a comparable monitoring platform The platform will also connect with external automation, CRM and intake systems that are being developed or managed separately. The selected developer must build the APIs, webhooks, database structures and application states required to support those integrations. Please identify any changes you recommend to the proposed stack and explain the technical and commercial rationale. Privacy and Security Requirements The platform may collect sensitive personal information. Privacy and security must therefore be treated as core product requirements rather than added after development. The build must include: * Clear and separate user consent where required * Disclosure of how submitted information is used and shared * Data minimization * Optional handling of particularly sensitive fields * Encryption in transit and at rest * Prevention of sensitive information appearing in URLs, analytics events or application logs * Strong row-level security * Role-based access controls * User-requested data deletion * Documented data-retention rules * Secure handling of uploaded documents * Appropriate administrative access controls * Auditability of important actions Please apply only if you are comfortable implementing and documenting these requirements. Performance and Quality Expectations * Responsive web application * Mobile-first consumer workflows * Provider workflows that remain usable on mobile devices * Support for current and prior major browser versions * Real-device testing on iOS * Strong mobile performance * Passing Core Web Vitals * WCAG 2.1 AA for consumer-facing workflows * Product analytics across major conversion funnels * Cookie-consent management * Error tracking * Uptime monitoring * Secure staging and production environments * Automated and manual testing appropriate for a production marketplace Native mobile applications are not included in this project. Expected Deliverables * Complete production-ready application * Source code stored in my GitHub organization * Repository access and ownership from the beginning of the project * Incremental commits throughout development * Accessible staging environment during the build * Production deployment * Database schema and migrations under version control * Environment-variable documentation * Technical setup and deployment documentation * Administrative-console documentation or walkthrough * Weekly written progress reports * Milestone-based staging demonstrations * Post-launch defect support All third-party accounts must be established under my ownership, with the development team granted appropriate access. Not Included in the Base Scope Please do not include the following in the initial estimate: * Native iOS or Android applications * Consumer financing integrations * Advanced provider CRM functionality * Enterprise account functionality * White-label licensing * Development of external AI agents * Third-party CRM workflow development * Third-party automation workflow development * Processing of the underlying service payment * Content writing * Brand identity or logo design You may identify features that would be substantially cheaper to build now rather than retrofit later, but list them separately from the base proposal. Ideal Candidate Strong applicants will have direct experience with several of the following: * Two-sided marketplaces * Lead marketplaces * Bidding, quotation or competitive-response workflows * Role-based consumer, provider and administrative dashboards * Stripe subscription billing * Usage-based billing * Supabase row-level security * Next.js server-side rendering * Geographic matching * Marketplace state management * Transactional email and SMS * Sensitive-data handling * Production SaaS launches Generic proposals that do not address the specific technical requirements of a two-sided marketplace will not be considered. What to Include in Your Proposal Please include: 1. Examples of relevant marketplaces or SaaS platforms you have built. 2. A clear explanation of your role in each project. 3. Whether you work independently or with a team. 4. Your proposed technical approach. 5. Your current weekly availability with an assumed start of November/December 2026. 6. A realistic preliminary calendar timeline. 7. A preliminary total cost range for the complete build. 8. Your preferred milestone and payment structure. 9. The areas you believe present the greatest technical or scope risk. 10. Your experience with Stripe subscriptions and usage-based billing. 11. Your experience implementing Supabase row-level security. 12. Confirmation that you can implement the privacy and security requirements. 13. Whether UI and UX design are included in your estimate. 14. What information or materials you would need before beginning development. I am interested only in estimates for the complete platform. Please do not propose dividing the project into an isolated frontend, partial backend or temporary no-code build. Shortlisted candidates will receive a detailed requirements document after screening and execution of an appropriate confidentiality agreement. They will then be asked to provide a module-by-module estimate, assumptions, exclusions, delivery schedule and fixed-price proposal. Please begin your proposal with the words “Marketplace Build” so I know you reviewed the posting carefully.