We’re looking for a hands-on Senior Mobile App Engineer to lead development of our React Native application that delivers near real-time, voice-to-voice translation. You’ll own core client features—from FaceTime-like calling and live captioning to buttery-smooth UI animations—and collaborate closely with our speech/ML, product, and backend teams to ship a high-quality, low-latency experience. Experience with React Native is required; with knowledge writing and Kotlin plugins a strong plus. AV experience is a plus.
What You’ll Do:
Build major app features:Own major product surfaces within audio/video calling, onboarding, growth features, etc.Implement native-quality UX in React Native with high-polish animations and transitions.
Real-time media & low latency:Integrate with our real-time translation backend and media pipelines.Work with (or introduce) WebRTC for A/V calls; handle audio routing,interruptions, and seamless crossfades from original to translated audio.
Performance, reliability, and quality:Optimise startup time, frame budget, memory, and jank.Instrument crash/error reporting; build resilience for poor networks and backgrounding.
Instrumentation & growth:Add analytics, deep-links, and attribution (e.g., PostHog, Branch or equivalents).Support A/B experiments, onboarding flows, notifications, and “call non-users” funnels.
Platform collaboration:Bridge native modules (Swift/Obj-C; Kotlin/Java) when RN needs deeper platform access (for example, writing callkit plugin)Partner with ML/infra teams on streaming APIs, caption timing, and voice pipelines.
Security, accessibility, and internationalisation:Implement privacy-first features, localisation/i18n, and accessible UI.
Must-Have Qualifications:
5+ years building and shipping consumer-grade mobile apps; 3+ years with React Native and TypeScript.Demonstrated ownership of a major app or feature used by real customers (App Store/Play Store).Strong UI/UX instincts with React Native animations (e.g., Reanimated,Gesture Handler; familiarity with Lottie or Skia is a plus).Experience integrating real-time or streaming features (sockets, media, or similar).Comfortable bridging to native: Swift/Objective-C (Kotlin/Java a plus).Fluency with mobile CI/CD, OTA updates (e.g., CodePush/EAS), crash reporting, and performance tooling.Excellent product judgment, collaboration, and communication; thrive in fast-paced, in-person startup environment.
Preferred Experience:
WebRTC (or VoIP stacks) for audio/video calling; familiarity with CallKit/PushKit (iOS) or ConnectionService/FCM (Android).iOS audio/video frameworks (AVFoundation, AVAudioSession, audio mixing/crossfades).Android media (AudioTrack/ExoPlayer), and/or Kotlin for parity features.Live captions, speech recognition, or audio UX on mobile.Analytics/attribution (PostHog, Branch or alternatives), deep linking, and growth experiments.Localization/i18n, accessibility, and app security best practices.Start-to-finish launch experience for a high-quality B2C app.
