Senior Full-Stack Engineer - Supabase (Part-Time)

*Engagement: Starts with 10 hours/week, can increase over time.* We’re looking for a backend-heavy full-stack developer to partner with a design-first founder building custom software for service-industry clients. The founder comes from 20+ years in product management, project management, UX, and web design. He works closely with clients to understand their messy operational workflows, turn them into polished prototypes, and build practical tools that replace spreadsheets, manual processes, and disconnected systems. The current projects are mostly B2B workflow apps: dashboards, intake flows, technician/admin portals, QR-code-based forms, status tracking, photo/documentation workflows, client-specific tools, and lightweight integrations. The ideal person is a technical build partner who can take a clear prototype and spec, design the backend architecture, build the Supabase infrastructure, connect the frontend, and push back when something should be done differently. The first engagement will likely start with a smaller QR-code workflow app for service companies, with potential to grow into larger projects and a long-term collaboration.} Responsibilities Design and build backend infrastructure using Supabase, PostgreSQL, Auth, RLS, Storage, Realtime, and Edge Functions. Create clean database schemas with proper relationships, indexes, constraints, and migration planning. Write secure Row Level Security policies for user-facing tables. Set up authentication flows, permissions, sessions, and access logic where needed. Build TypeScript/Deno Edge Functions for business logic, webhooks, scheduled jobs, and API integrations. Integrate third-party tools such as Stripe, Twilio, OpenAI, SendGrid/Resend, Zapier/Make, or client-specific APIs. Connect React/Tailwind frontends to the backend and help bridge the handoff between UI and infrastructure. Review existing backend work and suggest improvements without overcomplicating the product. Help turn prototypes into stable, scalable, production-ready applications. 3–6+ years of experience building production full-stack or backend-heavy web applications Deep hands-on experience with Supabase, including real shipped apps using RLS, Edge Functions, and Auth Strong PostgreSQL fundamentals: schema design, indexes, query optimization, constraints, and ability to read an EXPLAIN plan TypeScript / Node / Deno competence for building backend logic and Edge Functions Strong security instincts: RLS, input validation, permissions, and secrets management should be part of your default approach Clear written and spoken English for async handoff, documentation, and weekly Google Meet syncs Self-directed working style: able to take a spec doc and prototype, move independently, and surface questions in batches Strong communication skills, including the ability to explain tradeoffs and push back constructively when a better technical path exists A portfolio, case study, clickable prototype, or live/repo link that shows how you think and build Nice to have Experience with third-party API integrations such as Stripe, Twilio, OpenAI, SendGrid/Resend, Make/Zapier, or client-specific tools Comfort with React + Tailwind so you can help wire frontends to the backend Experience with service-industry tools, such as CRMs, scheduling systems, operations dashboards, intake forms, or field-service workflows A point of view on workflow and process design, including state flows, approval chains, dashboards, or operational logic Long-term, ongoing contractor relationship — not a one-off project Remote work, with LATAM timezone overlap preferred Flexible part-time setup: starting around a 10-hour weekly retainer, with potential to grow depending on fit and project flow High ownership and influence over technical direction Collaborative, low-bureaucracy environment