About the Role

Own the whole frontend of Mozart's real-time, multiplayer music creation platform in the browser — rendering architecture, state management, and delivery systems behind WebGL rendering, WASM audio, background jobs and social features.

Key Responsibilities

Own the hybrid server/client-side rendering architecture (data fetching, streaming, caching, code splitting)
Own state management for DAW sessions, live collaborators and social state
Own the CI/CD delivery pipeline across web and mobile, with feature flags and canary deploys
Build the media-heavy social layer: feeds, audio previews, profiles, publishing
Make production observable, propose and lead structural refactors
Own frontend testing, from component stories to agentic end-to-end suites

Requirements

5+ years of professional experience architecting and refactoring large React codebases
Production experience with SSR (TanStack Start, Next.js or similar)
Experience with server-push architecture and store architectures (Zustand, Redux, Jotai)
Deep browser/DevTools mastery and delivery infrastructure experience
Comfortable working in agent-native, AI-assisted workflows

Details

In-person role from Mozart AI's Central London office. Right to work in the UK required (no visa sponsorship, but relocation support to London is offered). Significant equity offered; Mozart AI has raised over $7M from Balderton Capital and other investors.

Founding Frontend Engineer