Senior Full Stack Software Engineer

About Matter

At Matter, we believe that nutrition is medicine and that access to the right nutrition protocols is one of the best indicators of longevity and wellbeing. To that end, Matter is the world’s first fully integrated nutrition platform that tracks, recommends, and prepares everything you need to eat to live a long life.

Matter ingests your health data, goals, and meals to build your daily menu, auto-order and deliver it, tune your supplements, and track your macros to the gram.

Personalized nutrition, run end to end by an intelligence that learns what your body needs.

The Role

We're hiring a Senior Full-Stack Engineer to build our consumer mobile app and the AI features inside it.

You'll work closely with the Director of Engineering and own features end to end, from the React Native UI down to the backend endpoints and LLM pipelines that power them.

Your specialty is building highly engaging, dynamic mobile experiences that feel fast and alive, increasingly powered by AI / LLM components (think meal analysis, nutrition intelligence, and conversational features).

What you'll do

• Build and ship features in our React Native / Expo consumer app. Polished, performant, animation-rich UI

• Design and integrate LLM-powered features end to end: prompt design, streaming responses, tool use, and wiring model outputs into a great mobile UX

• Build the backend behind those features: REST endpoints, data models, and AI provider integrations

• Own performance and responsiveness: smooth interactions, offline tolerance, fast data fetching and caching

• Collaborate with product and design to turn ideas into engaging, measurable experiences

• Instrument features with analytics and iterate based on real usage

What we're looking for

• 5+ years of full-stack engineering, with strong React Native / Expo (or heavy React) experience shipping production consumer apps

• Demonstrated ability to build dynamic, high-quality mobile UI: animation, gestures, responsive layouts, attention to detail

• Hands-on experience integrating LLMs into products

• Solid TypeScript and comfort across the stack: Node.js / Express backends and PostgreSQL

• Experience with modern mobile state and data patterns (e.g. Zustand, TanStack React Query)

• Product sense: you care about how it feels, not just whether it works

Nice to have

• Experience with Expo Router, native modules, and EAS build/release pipelines

• Familiarity with local persistence (expo-sqlite), offline-first patterns, and real-time sync

• Background in nutrition, health, food, or another data-rich consumer domain

Benefits

Competitive pay and the full range of benefits you'd expect, including health coverage and paid time off.