💡 About Liftoff Our Mission: Making the world a healthier place by gamifying fitness Liftoff is the Duolingo of fitness, empowering anyone to start and stay at the gym so they develop healthier, more powerful habits. We’re a mission-driven team that moves fast, owns the details, and does the work. We’re fully bootstrapped, profitable, and built from zero to $10M+ ARR in under three years. 🌟 About the Team You'll join the Product team and work closely with the Head of Product, collaborating with Engineering, Design, and Growth Our product is the engine behind everything: retention, monetization, and ultimately revenue. This role is for someone who wants end-to-end ownership over backend reliability and experiment velocity, and loves shipping. 🎯 About the Role We're hiring a Full-Stack Engineer to ship product features and experiments end-to-end. Your core focus areas: • Feature delivery across the stack in TypeScript, from React Native screens to Supabase data • Polished, correct UI, shipped to the standard of the design, not an approximation of it • Experiment infrastructure and instrumentation • Clean, performant API and data access • Cross-functional shipping with Product, Design, and Growth This is a high-ownership role. You'll take a problem from spec to shipped, work with our existing team/resources, and own the outcome, not just your slice of it. ✅ What Success Looks Like • Features and experiments that go out end-to-end without stalling on handoffs • UI that ships pixel-correct and feels right; spacing, states, edge cases, and transitions handled without needing a review pass to catch them • A high-velocity experiment pipeline: clean instrumentation → fast implementation → reliable measurement → iteration • A product that stays fast and stable as usage grows; schema changes land safely, queries stay efficient • Shipped improvements that compound (reusable experiment patterns, better event tracking, faster deploys, fewer incidents) • Strong operating cadence with crisp communication on what's shipping, why, and what it did 🛠️ What You’ll Do • Ship features end-to-end • Build the front end in TypeScript with React Native (Expo); typed, readable, and maintainable by the next person • Implement designs faithfully: correct spacing and type, all states (loading, empty, error), and the edge cases the mock doesn't show • Write and run migrations and deploy schema changes safely; keep the data model clean as the product grows • Stay conscious of load and performance - catch the slow query or the runaway request pattern before users do • Ship experiments and instrumentation • Partner with Product/Growth to implement A/B tests and feature flags via Statsig • Ensure every experiment has clean event tracking and reliable data • Build reusable patterns that reduce experiment cycle time • Use data to drive decisions • Instrument events properly so the team can trust experiment results • Spot measurement issues (leaky cohorts, misconfigured flags, underpowered tests) before they corrupt decisions • Collaborate cross-functionally • Work with Product and Growth to align experiment implementation with the roadmap • Work with Design to turn Figma into shipped UI in React Native / Expo • Contribute to prioritization by bringing technical feasibility and effort estimates 🔍 You’ll Likely Succeed If You Have We don’t expect you to check every box. We care most about ownership, judgment, and shipping. • Professional full-stack experience shipping to production • Strong TypeScript — it's the language of the whole stack here, front end included • Comfort on both sides: modern front-end (React / React Native or similar) and Node.js against a relational database (Postgres preferred) • A real eye for detail; noticing unwanted 4px gaps, missing empty states, animation stutters, and fixing it without being asked • Working knowledge of schema design, migrations, and query performance, enough to make changes safely without needing a specialist • Hands-on experience with experimentation infrastructure: feature flags, A/B tests, event tracking • Demonstrated ability to ship autonomously in a fast-paced, low-structure environment • Clear written communication; can document decisions, write specs, and share learnings 🌱 Bonus Attributes • UX instinct — you can tell when a flow doesn't feel right, not just when it doesn't match the spec, and you can articulate why and push back on a design • Experience with our specific stack: Supabase, Vercel, tRPC, Statsig, RevenueCat • Background in subscription/consumer apps — understanding of trials, paywalls, LTV, ARPU • Experience with AI-assisted development workflows • Prior experience at a fast-moving startup where you wore multiple hats • Motion/animation implementation (Rive or similar) 🧰 Tools & Tech Stack You don't need prior experience with every tool, but you should be excited to learn and ship in this stack. • Language: TypeScript, end to end • App: React Native (Expo) • Frontend: Figma, Rive • Backend: Supabase, Vercel, tRPC, Node.js • Monetization: RevenueCat, Superwall • Experimentation / Analytics: Statsig 🙌 At Liftoff, You’ll Enjoy • Autonomy and Ownership: you are in charge of your time at Liftoff. Decide what you want to do, align with leadership, and go for it. • Top-of-the-Market Cash & Equity Compensation: we pay for high performers. • A World-Class Team: low-ego, high standards, and real ownership. 🤝 Interview Process • Hiring Manager Screening • Take-Home Challenge (backend task + frontend implementation) • Technical Deep Dive (live walkthrough + system design extension) • Work week trial (paid - simulating real work environment) 💰 Compensation and Benefits • Competitive cash (based on level and scope) • Company-paid lunch every day (if you’re in office) • Lifetime Liftoff Pro membership 🌍 Equal Opportunity Liftoff is an equal opportunity employer. We hire and grow talent based on strengths, potential, and performance, and we are committed to buil