Founding Frontend Engineer (£120k + Equity) at Mozart AI

Job Title

Founding Frontend Engineer

Salary

£120k + Equity

Company Description

Mozart AI is a $6M seed-funded startup backed by Balderton Capital building a generative audio workstation that gives artists AI-powered control over stems, instruments, and composition.

Job Description

As Founding Frontend Engineer at Mozart AI, you will own the entire frontend architecture, managing a complex stack including React, WebGL, and TanStack Start. You’ll tackle extreme performance challenges—like rendering 30k rectangles at 60fps—and build the “backend of the frontend” to ensure a seamless, professional experience for music creators worldwide.

Location

London, UK

Why this role is remarkable

• Work on a performance-critical generative audio workstation featuring a WebGL renderer running at 60fps and managing 3M lines of React code.
• Join a high-intensity, $6M seed-funded team backed by Balderton Capital as a founding member with significant equity and technical ownership.
• Build a generational product that moves beyond basic AI generation into professional DAW features like stems, instruments, and individual note control.

What You Will Do

• Architect and own the “backend of the frontend,” including complex state management (Zustand), SSR/CSR strategies, and real-time streaming via WebSockets.
• Develop and maintain a high-performance design system and testing infrastructure (unit, integration, and e2e) to support rapid, large-scale consumer deployments.
• Collaborate directly with the CTO to shape the technical direction of the product and integrate sophisticated AI-driven audio features into the UI.

The ideal candidate

• Approximately 5 years of professional frontend experience with deep expertise in TypeScript, React, and modern state management libraries.
• Proven “Startup DNA” with experience as a founding engineer or early employee at a fast-growing consumer brand with high engineering standards.
• Ability to thrive in an intense, in-office London environment, working a 6-day week to build a category-defining creative tool.

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