Senior Frontend Engineer (Pass)

Proton

ES - Barcelona💼 Full-time💰 $54,000–$106,000🗓 2026-07-20 → 2026-09-26

Core

Build and maintain secure, privacy-focused web and desktop applications, including browser extensions, for Proton Pass.

Role type

Senior Frontend Engineer (Web/Desktop/Extensions)

Builds

Proton Pass (password manager), browser extensions, and desktop applications

Domain

Privacy technology, cybersecurity, consumer software

Deliverable

production ML models | product features

Required skills

TypeScript, JavaScript ecosystem, browser internals, extension APIs, desktop application frameworks, CI/CD, software engineering best practices, testing strategies

Preferred skills

MV3 browser extension development, Electron, WebAssembly, Rust, service-worker architectures, event-driven systems, cryptography concepts, UX/accessibility/localization, application monitoring

Technologies

TypeScript, JavaScript, Electron, WebAssembly, Rust

Responsibilities

Develop new features and deploy high-quality user experiences; collaborate with cross-functional teams to execute initiatives; conduct code reviews and optimize performance; develop and implement comprehensive testing strategies

Seniority

Senior, hands-on IC

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About Proton

Proton was founded in 2014 by scientists from CERN on a simple truth: privacy is a fundamental human right. Since then, we’ve built the world’s largest encrypted email service (Proton Mail) and expanded into Proton VPN, Proton Drive, Proton Pass, and Proton Calendar—tools used by millions globally to protect their freedom, fight censorship, and keep their data safe. In some situations, Proton has literally helped save lives!