📍 Location: London, UK – In-person

• Employment Type: Full-time
• In-office expectation: Work from our office in Central London
• Eligibility: You must have the right to work in the UK – we don't sponsor visas at the moment, but we support relocation to London

About Mozart AI

Mozart AI is music's first creation network, where the world goes from listening to music, to making it together, to being known for it. 1.5 billion people can play an instrument. We're building the products that turn them into artists, and turn their fans into the next ones. Our customers love us, and include everyone from grandmas using Vibe sessions to Grammy winners using the Studio. Music is having its first explosive moment of creation-driven consumption, and we aspire to shape that world to preserve the social and fun elements of music creation.

We've raised over $7M from Balderton Capital (backers of Revolut) and several Silicon Valley legends like Kevin Hartz and Emery Wells, who have backed companies like Uber, Spotify, Reddit, and other massive consumer outcomes.

We're a small, talent-dense team building the future of music from our London office. We operate with high ownership, high velocity, and low-ego collaboration — specialist generalists who work hard, learn fast, and ship relentlessly. We care deeply, move fast, and we're here to build something that outlives us.

About the Role

Mozart combines music creation, real-time collaboration, and a creator community in one product, and the backend has to hold all of it together as usage scales. You'll build the backend foundation that carries Mozart from hundreds of thousands of users to millions, and you'll do it while the product changes every week.

This is an intense, in-person role, built for people who want massive impact and grow their careers faster than anywhere else.

What You'll Do

• Own the API surface. Design the typed, end-to-end contracts that web, mobile, and internal admin tooling consume
• Build the media generation backbone. Design how every AI job moves from request to result across many internal and external providers and integration styles, and how the steps that follow chain together without ever losing a job. The result reaches every collaborator in the session, not just the one executing the job.
• Run media at scale. Upload, transcoding, storage, and CDN delivery for audio, video, and images
• Design the core data model. From the state of a DAW session (projects, songs, tracks, clips) to the social graph around it (profiles, follows, feeds, publishing, moderation), build schemas that are deeply relational, versioned, and consistent across every client.
• Ship real-time collaboration. Presence, shared state, and conflict resolution for multiple people editing the same session at once