Sr. Front-End Mobile Engineer, Aza & PXT AI

Job description

PXT AI builds AI-powered products that serve Amazon's global workforce. Our flagship product is Aza (A to Z Assistant), an AI Assistant used daily by hundreds of thousands of Amazonians to find information, complete tasks, and improve productivity.

Aza is built on AWS technologies—Bedrock for RAG responses and multi-agent orchestration, and Nova for Voice. It integrates content and business logic from domains across Amazon (PXT, IT, Sage, GREF, Approvals) and is accessible through A to Z on desktop, mobile, Slack, and as a Chrome extension.

We're looking for a Senior Front-End Mobile Engineer to build the mobile experience for Aza on iOS and Android. This is a hands-on, craft-focused role where you'll own high-fidelity conversational and voice interfaces—the animation, the motion, the keyboard behavior, the theming—and work shoulder-to-shoulder with designers to turn intent into shipped product. If you care about the last 5% of polish that makes an app feel native, this is that job.

The ideal candidate has deep React Native expertise, experience building conversational or voice-driven interfaces, and a track record of shipping high-quality mobile applications at scale. You'll work across the full mobile stack—from UI-thread animations to native modules to CI/CD pipelines—and raise the bar for mobile engineering across the team.

Key job responsibilities

- Build and own the mobile experience for Aza across iOS and Android using React Native

- Implement complex UI animations and gestures using Reanimated (UI-thread animation), gesture handling, custom navigation transitions, and spring physics

- Build conversational UI components: streaming/token-by-token rendering, markdown rendering, autoscroll, prompt suggestions, and nested prompt menus

- Implement voice interaction features: live audio visualizers/waveforms, mic and session state management, wake-word handling behind feature flags, and text-to-speech playback using Amazon Nova and Polly

- Integrate real-time client features—streaming responses from Bedrock, connection recovery, and long-lived session state

- Build and extend the shared component library and design-token system (spacing, color, typography) used across PXT AI products

- Implement multi-brand theming at scale—supporting light/dark modes and design variations across one codebase

- Own keyboard, safe-area, and bottom-sheet interactions: composer-to-keyboard sync on the UI thread, detents, and edge-to-edge layouts

- Drive React Native version upgrades and adopt the New Architecture (Fabric, TurboModules) to improve performance and maintainability

- Ensure accessibility (WCAG) in mobile: screen-reader semantics and announcements, dynamic type and font-scale capping, focus order, and touch-target sizing

- Implement internationalization and localization across 8+ languages, including RTL and text-expansion-safe layouts

- Build feature-flagged, incremental rollout workflows—gating, staged launches, and clean revert/re-land patterns

- Partner closely with product designers in Figma, providing implementation insight and pushing back constructively to improve designs

- Write unit and component tests for UI code, and contribute to CI/CD infrastructure and release pipelines using AWS CDK or equivalent

- Practice secure client engineering: no secrets in the client, backend-proxy patterns for credentialed calls, and supply-chain hygiene in package dependencies

- Mentor other front-end engineers through code review and knowledge-sharing, raising the quality bar for the team