Senior React Native Engineer in London

About MILE

MILE is the new members‑only shopping destination redefining luxury commerce. We offer access to a curated, seasonless catalogue of the most sought‑after products from globally renowned fashion houses—at unmatched prices. Built at the intersection of technology and fashion, MILE delivers a seamless, elevated experience for both consumers and brands. Our mission is to become the leading digital destination for luxury—where exclusivity, value, and exceptional design converge.

What We're Looking For

We’re looking for a Senior React Native Engineer to join our core engineering team. This is a high‑impact, high‑ownership role: you’ll be building the mobile experience that defines what luxury commerce feels like on a phone. You won’t be consuming a design system—you’ll be authoring one. You won’t be integrating a checkout—you’ll be owning it end to end, from gesture to payment confirmation.

Responsibilities

• Own and evolve our Tamagui‑powered cross‑platform design system—extending base components, token architecture, themed variants, and platform‑specific behaviour across iOS, Android, and web.
• Build and maintain complex, gesture‑driven UX flows that feel genuinely native on both platforms—animations, haptics, swipe interactions, and transitions that meet a luxury bar.
• Architect and implement efficient component hierarchies with disciplined re‑render control—leveraging Zustand, Redux selectors, and React Compiler’s automatic memoization model.
• Work within and extend our Orval‑generated TanStack Query v5 API layer—understanding the codegen contract, managing cache strategies, and handling offline‑first persistence with MMKV.
• Own payment flows end to end—Stripe React Native SDK, Apple Pay, Google Pay, and the native payment sheet UX that makes or breaks checkout conversion.
• Integrate and maintain native modules—bridging JS and native layers, debugging across the JSI/Fabric boundary, and handling library compatibility in the new architecture.
• Own our EAS build pipeline across development, internal, and store profiles for both QA and production environments, including OTA update channel management.
• Drive Android polish to the same standard as iOS—predictive back gesture, ripple behaviour, elevation model, font rendering, and status bar handling.
• Contribute to and enforce best practices around component architecture, dependency management, and cycle detection using our existing tooling (madge, dependency‑cruiser).
• Work closely with design to pixel‑match implemented components against specs, and push back or propose when implementation constraints require a better solution.
• Mentor junior and mid‑level engineers, conduct thorough code reviews, and raise the quality bar across the mobile codebase.

Qualifications

React Native & Architecture

• 6+ years of professional React Native experience shipping to production on both iOS and Android.
• Deep understanding of the new RN architecture—JSI, Fabric, TurboModules—and what it means for synchronous native calls, bridging strategy, and third‑party library compatibility.
• Proven experience authoring or deeply extending a compile‑time UI kit (Tamagui, NativeWind, or equivalent) — not just consuming components but owning the token system, variant model, and platform override layer.
• Strong grasp of React’s reconciliation model and a principled approach to re‑render elimination—selector patterns, referential equality, and understanding what React Compiler automates versus what it doesn’t.

Animations & Native Feel

• Expert‑level Reanimated 3—worklets, useSharedValue, useAnimatedStyle, useAnimatedScrollHandler, shared element transitions, and gesture‑coupled animation state via Gesture Handler 2.
• Experience designing and implementing haptic feedback as a first‑class interaction tool—considered approach to timing, intensity, and platform differences between iOS Taptic Engine and Android vibration API.
• Demonstrated ability to make Android feel genuinely native—predictive back, edge‑to‑edge layouts, Material ripple, elevation shadows, and type rendering all count.

Data, API & State

• Deep experience with TanStack Query v5—persistence strategies using react‑query‑persist‑client, stale‑while‑revalidate cache design, and offline‑first hydration patterns.
• Comfortable working within a codegen API layer (Orval or equivalent)—understanding the OpenAPI contract, extending generated hooks without breaking the pipeline, and knowing when to step outside it.
• Solid understanding of layered storage architecture—namely in‑memory state, MMKV for performance‑critical persistence, redux‑persist for structured app state, and secure storage for sensitive data. Knowing when to use each and why.

Payments & Native Integrations

• Production experience with the Stripe React Native SDK—payment intents, setup intents, payment sheet customisation, and 3DS handling.
• Experience integrating Apple Pay and Google Pay—entitlement configuration, merchant validation, and the native payment sheet UX.
• Hands‑on experience writing or debugging native modules—bridging existing native SDKs, resolving CocoaPods/Gradle conflicts, or debugging issues that only surface at the native layer.

Build, Delivery & Tooling

• Deep familiarity with the Expo/EAS ecosystem—prebuild lifecycle, build profile configuration, OTA update channels, and diagnosing build failures that only surface in CI.
• Experience with on‑device Storybook workflows for component development and design QA.
• Comfortable with dependency graph tooling (madge, dependency‑cruiser) and proactive about preventing circular dependency accumulation in large codebases.

Bonus Points

• Experience integrating analytics and observability at the component level—PostHog funnels, Datadog RUM, Bugsnag with source map upload pipelines.
• Familiarity with Branch deep linking—short link creation, universal link configuration, AASA setup, and debugging link resolution failures.
• Experience with push notification pipelines spanning OneSignal, Klaviyo, and Firebase—segmentation, in‑app messaging, and delivery debugging.
• Exposure to Appium/WebdriverIO for mobile automation on real devices.
• Passion for fashion, luxury, or consumer product—genuine care about the end user experience goes a long way here.

Benefits

• Opportunity to play a key role in shaping the future of the company.
• Collaborative and innovative work environment.
• Career growth opportunities in a fast‑growing organisation.

Let’s build something people talk about. Together.