Leon David

Senior React Native developer

I ship mobile products end to end.

Ten years building React Native apps — field ops for airport technicians, consumer platforms at Airbnb and Vogue, and my own indie work. This site is a short list of the things I care about most.

See the featured work leonzetechwiz@gmail.com
Featured work

Two apps I built, front to back.

Cosmic Solo home screen
Launching soon

Cosmic Solo

An AI-powered astrology app that helps you decide, not just scroll. On-device natal chart computation and grounded guidance.

Role
Solo — design, engineering, product
Stack
React Native · Expo SDK 54 · TypeScript · Redux Toolkit · astronomia · OpenAI
Read case study
Life In Character avatar screen
Personal build

Life In Character

A Habitica-inspired RPG habit tracker. Built as a personal engineering study in gamification mechanics, sprite-layered avatars, and Redux-at-scale.

Role
Solo — design, engineering
Stack
React Native · Expo SDK 54 · TypeScript · Redux Toolkit · Redux Persist
Read case study
Selected experience

Ten years across enterprise and consumer mobile.

  1. DFW International Airport
    Senior React Native Developer · Contract
    Next-generation field ops app. ArcGIS migration, offline-first architecture, encrypted GPS breadcrumbs. 150+ iPads deployed.
    Read case study
    2025
  2. Emcee
    Senior Full-Stack React Developer
    Social commerce platform. Led Creator Analytics mobile module and Next.js brand portal. Apollo GraphQL, Stripe Connect, Algolia.
    2024 – present
  3. Antares Technologies
    Senior React Native Developer
    Led development and 3-year maintenance of VoCap — cross-platform voice recording and editing app. Native module integration and multi-arch builds.
    2022 – 2025
  4. Techfield
    Senior React Consultant
    Pest-control technician workflow app. Modular React components, Redux state, AWS Lambda backend.
    2022
  5. Airbnb
    Senior React Native Developer
    Real-time order tracking, Apple Pay / Google Pay native modules, geolocation-based routing. Hermes and Redux performance work.
    2019 – 2021
  6. NerdWallet
    Senior React Native Developer
    Predictive autocomplete for financial forms, Express + MongoDB APIs, Material Design across iOS and Android.
    2017 – 2019
  7. Vogue
    React Native Developer
    Vogue Runway Fashion Shows app — cross-platform, offline mode, Mapbox integration. 1M+ downloads.
    2015 – 2017
  8. Discord
    React Native Developer
    Reusable UI component library, React Navigation + Redux, chat performance work.
    2015
  9. Sanmina Corporation
    iOS & Android Native Mobile Developer
    Biometric auth, Objective-C to Swift migration, Alamofire + Retrofit API layers.
    2013 – 2015
How I work

I like mobile work because the constraints are real. Offline, slow networks, older devices, battery, native modules — problems that force you to think about architecture rather than hide behind it.

I've spent the last few years on apps that field technicians actually use in the real world and on consumer platforms where performance is the feature. I care about shipping honest products, writing TypeScript that other people can read, and resisting the pull of premature abstraction.

If you're building a mobile product and need a senior hand on it — contract or full-time — I'd like to hear about it.