Full-Stack Developer for SaaS MVP

We need a full-stack developer to build a SaaS MVP with a form, API integration, Stripe for payments, email verification, and Google Sheets for data management. The ideal candidate will have experience in both front-end and back-end development, ensuring seamless integration of all features. This project requires a proactive approach to problem-solving and a commitment to delivering high-quality results. STEP 1 — Input validation and classification with AI API STEP 2 — Cache check STEP 3 — Product selection STEP 4a — Email verification flow (Free Tier B only) STEP 4b — Stripe payment flow (Paid Tiers) STEP 5 — Processing engine (Free Tiers only) STEP 6 — Result display (Free Tiers only) STEP 7 — Data logging to Google Sheets Additional technical requirements: — Founder whitelist: a list of email addresses in config bypasses the 30-day cache check for unlimited internal testing — All sensitive configuration (API keys · weights file · whitelist) stored in environment variables or server-side config files only — never in client code — Deployable on Railway or equivalent PaaS — Simple enough to be maintained by a single junior developer after handover Tech stack: Your choice. We are open to your recommendation. Keep it simple and maintainable. Server-rendered HTML is preferred over a heavy SPA framework for this MVP. Database can be lightweight (SQLite or PostgreSQL). Do not over-engineer! What we provide before development starts: — Full technical brief (after NDA) — The prompt strings for the AI API calls — The JSON configuration file structure — Following layouts: website homepage, about, price — The result page layout (design file) — All API credentials (Anthropic, Stripe, Google Sheets) — The disposable email blocklist source NDA and IP assignment agreement required before receiving the full brief. This is non-negotiable. We will send the agreement within 24 hours of selecting a candidate. Deliverables: — Complete working application deployed to a live URL — Source code in a private GitHub repository (you add us as owners before final payment) — README covering setup, environment variables, and configuration file format — End-to-end test with real inputs confirmed working in production Budget: Fixed price only. No hourly. Please include in your proposal: - Your total fixed price with a breakdown by component - Your proposed tech stack with a one-line reason for each choice - Two or three examples of past projects involving API integration, form flows, and payment processing - Your estimated timeline in weeks - Confirmation that you will sign an NDA before receiving the full brief — proposals without this confirmation will not be considered We will shortlist within 48 hours of posting and schedule a 10-minute screening call with top candidates before sharing any further details.