About the Role

Mozart AI is building music's first creation network. You'll build the backend foundation that carries Mozart from hundreds of thousands of users to millions, owning the API surface, media generation pipeline, and real-time collaboration.

Key Responsibilities

Own the typed, end-to-end API surface consumed by web, mobile and internal admin tooling
Build the media generation backbone for AI jobs across internal and external providers
Run media at scale: upload, transcoding, storage and CDN delivery for audio, video and images
Design the core data model for DAW sessions and the social graph around them
Ship real-time collaboration: presence, shared state and conflict resolution
Own payments and monetization via Stripe and RevenueCat
Make the platform observable and safe, and build CI/CD for AI agents

Requirements

5+ years of professional experience building APIs with multiple consumers
Experience with multi-step, multi-service systems and complex domain models on live data
Experience building media pipelines at scale
Experience with billing and entitlements (subscriptions, credits, refunds)
Works with coding agents daily and designs agent-verifiable environments

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 Backend Engineer