Health & fitness (mobile) · Fueld · my own product

Fueld — a fitness & nutrition platform, launching soon

Fueld is my own product: a fitness and nutrition tracking app built end to end — React Native + Expo, a Fastify API, and Firebase, in one typed Turborepo monorepo. Coming to the App Store.

Published July 15, 2026

App Store soon
Status
launching shortly
Expo + Fastify
Mobile + API
RN new architecture, typed backend
Monorepo
One codebase
Turborepo + pnpm, shared types

What it is

Fueld is a fitness and nutrition tracking platform I’m building end to end — the app, the API, and the infrastructure — as a single typed system. It’s the clearest expression of how I like to build: shared contracts, a tested core, and a decision log kept as I go.

How it’s built

  • Mobile: React Native + Expo (SDK 52, new architecture), file-based routing with expo-router, Zustand for state.
  • API: Fastify on Node + TypeScript, typed against the same shared package the app uses.
  • Data & auth: Firebase — Firestore, Authentication, and Storage — with the full Emulator Suite for local development.
  • Monorepo: Turborepo + pnpm workspaces. Shared types, constants, and the domain math (BMR/TEE, macro solver) live in one shared package with its own tests.
  • Discipline: the architecture and the “why” behind each decision live in an ARCHITECTURE.md decision log alongside the code.

Status

In final stretch — coming to the App Store soon.

Frequently asked

What is Fueld?

A fitness and nutrition tracking app — log food and training, and see the numbers that matter (BMR/TEE, macros) computed from a shared, tested core.

Why build it as a monorepo?

Shared TypeScript types flow from the Fastify API straight into the Expo app, so a contract change is one edit in one place — the client and backend can’t drift out of sync. The domain math (BMR/TEE, the macro solver) lives in a shared package with its own tests.

What’s the stack?

React Native + Expo (SDK 52, new architecture) with expo-router, a Fastify + TypeScript API, Firestore for data, Firebase Auth and Storage, and Zustand for state — with the whole thing wired for local development on the Firebase Emulator Suite.

Services: Platform & backend engineering, Integrations

  • react-native
  • expo
  • fastify
  • firebase
  • turborepo
  • typescript

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