Frontend Engineer (Lumo)

Proton seeks a Mid-level Frontend Engineer to build responsive, high-performance interfaces for Lumo, its privacy-focused AI assistant, based in Geneva.

The company is expanding its Lumo AI team and needs an engineer to transform design concepts into reliable, fast user interfaces. This position focuses on delivering a seamless experience while adhering to strict privacy standards.

Responsibilities

• Convert UI mockups into production-ready React components.
• Connect frontend components with backend services using TypeScript and modern data-fetching patterns.
• Ensure pages load instantly, even on slower connections, by optimizing performance.
• Work closely with product managers, designers, and engineers to deliver features from start to finish.
• Maintain code quality by writing tests, documenting decisions, and participating in code reviews.
• Identify and resolve user experience friction points before they impact customers.

Requirements

• Deep expertise in React development.
• Strong foundation in TypeScript and JavaScript.
• Experience with state-management and data-fetching libraries.
• Commitment to writing clean, maintainable code without shortcuts.
• Effective communication skills and openness to giving and receiving feedback.
• Proactive problem-solving mindset, identifying issues and acting without waiting for instructions.

Nice to have

• Familiarity with AI or large language model products.
• Python scripting experience for tooling or data tasks.
• Understanding of distributed systems and observability stacks.
• Practical experience with design tools like Figma.

About the company

Proton operates Lumo with a zero-access encryption model, ensuring no server-side logs are kept and conversations remain completely confidential. The company prioritizes user privacy and data protection in all its services.

• Lumo uses zero-access encryption to protect user data.
• No server-side logs are stored, ensuring complete confidentiality.
• Conversations remain private and secure.