📍 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, 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

You'll own the Mozart mobile app end to end, React Native and Expo on top, Swift and Kotlin where the platform demands it. Generations, multiplayer sessions, background audio, offline projects, and cloud sync all have to run smoothly on a phone, and you'll build the foundations that let us ship every week without breaking any of it.

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 app. Architecture, state management, and navigation for our React Native and Expo app, on the same backend contracts the web app uses, with startup, frame rate, memory, and battery measured and tracked.
• Make a complex product feel simple. Music, video, and image generation, editing, collaboration, listening, and a social network in one app. You'll design the navigation model where everything is one or two taps away and it feels like one coherent product.
• Bring multiplayer to the phone. Presence, shared session state, and conflict resolution that survive backgrounding and network switches.
• Build for background and offline. Own the persistent job system on the phone: generations that finish while the app is closed, uploads and downloads that survive app kills, local songs and projects, and sync that resolves cleanly on reconnect.
• Make audio first-class. Background playback, system controls, interruptions, Bluetooth and AirPlay, and multi-track playback that stays in sync on a phone.
• Build the social layer for touch. Media-heavy feeds at full frame rate, audio previews, publishing, sharing into the platforms people already use, and push notifications for jobs, collaborators, and social activity that deep-link into the right screen with state already loaded.