Senior React Native Engineer; Latam & North America)

Objective-C

Kotlin

Swift

C++

Work fully remote, globally

Join a team spread across the world and enjoy true location freedom while collaborating with talented engineers everywhere.

Work with top brands

Riot Games, Fox, Coinbase, Epic Games, and so much more.

Gamified community you’ll love

Engage in online events, compete in challenges, and attend Outposts and summits that bring X-Teamers together learning, connecting, and leveling up globally.

Enjoy flexible schedules, wellness stipends, and support to make sure you’re thriving both professionally and personally.

This is a contractor role through X-Team. You'll own the mobile architecture behind a real-time trading experience - the kind of app where a dropped frame during a fast market means a trader misses a price. Every screen you touch, from a candlestick chart re-rendering thousands of points a second to an options chain repainting under high-frequency updates, has to hold its frame budget while real market data pushes against it.

The legacy bridge is gone. This isn't a New Architecture migration project - it's about going deep on JSI, Fabric, Turbo Modules, and bridgeless mode, and setting the standards every other engineer on the team builds against.

Open to candidates based in North America or Latam

8+ years building production mobile applications, including 5+ years in React Native at senior level or above

Demonstrable architect-level ownership — you've designed a mobile architecture that other engineers built on for years, not just delivered features inside one

Deep, hands-on experience with React Native's New Architecture: JSI, Fabric, Turbo Modules, Codegen, and bridgeless mode, including custom native modules and components you wrote yourself

Strong native iOS and Android skills:
Swift/Objective-C++ and Kotlin, with real comfort in C++ for shared cores or performance-critical paths

Proven multithreading work in React Native: worklets, worklet runtimes, Reanimated internals, background runtimes, and the serialization/lifetime rules that make them safe

A track record of sustained 60-120fps under real-time data load, with concrete before/after numbers you can walk through

Real-time data experience: high-message-rate Web Socket streaming, back pressure handling, binary protocols, and architectures that decouple ingest rate from render rate

High-performance charting experience in React Native - Skia, GPU canvas, or a custom native renderer - beyond dropping in an off-the-shelf chart library

Expert-level profiling across Hermes, Perfetto/Systrace, Instruments, React Dev Tools, and Flashlight

Experience at a trading, brokerage, crypto exchange, or high-frequency fintech app, or comparable real-time consumer scale elsewhere

Options-specific product work: options chains, multi-leg order tickets, greeks, payoff diagrams, implied volatility surfaces

Nitro Modules, or other experience reducing JSnative call overhead on hot paths

Open source contributions to the React Native ecosystem, or conference/blog work on RN performance

Experience in a regulated environment: security review, certificate pinning, tamper/jailbreak detection, auditability, accessibility compliance

Experience running OTA/Code Push-style release infrastructure with feature-flagged rollouts

Measures before touching code — diagnoses whether a stall is JS thread, UI thread, commit phase, GC, or GPU before reaching for a fix

Comfortable being the final call on hard architectural trade-offs, like deciding when a screen needs a native fallback and owning both sides of it

Writes the design docs and runs the architecture reviews, not just the code — raises the bar for everyone around them

Treats a dropped frame as a bug, not a nice-to-have

Mentors naturally, pairing on the…