Responsibilities

Implement privacy-improving, anti-tracking, and threat-intelligence protections in Firefox to mitigate tracking and phishing.

Implement architectural improvements to Gecko, the browser engine underlying Firefox.

Build performant, low-latency, and maintainable C++, JavaScript, and Rust software.

Independently scope, deliver, and improve complex features within tight release windows.

Work asynchronously with a geographically distributed team and communicate technical decisions clearly.

Requirements

Bachelor’s degree in computer science, engineering, or a related program, or equivalent work experience.

At least 4 years of experience programming in C++ and Rust.

Strong background in memory safety, multithreaded system architecture, or raw data-stream manipulation.

Proven ability to onboard quickly and deliver complex software projects.

Excellent written and verbal communication skills.

Preferred: experience with Gecko, Chromium, WebKit,



or web-engine runtime abstractions.

Preferred: experience or strong interest in ML pipelines for internal developer workflows, web architecture, web privacy and security models, client-side data structures, statistical modeling, Python, and SQL.

Benefits

Performance-based bonus plans for eligible employees.

Retirement contributions with immediate 100% vesting.

Quarterly company wellness days, country-specific holidays, and a birthday day off.

One-time home-office stipend and annual professional-development budget.

Quarterly well-being stipend and paid parental leave.

Employee referral bonus program and other country-dependent benefits including life/AD&D;, disability, and EAP coverage.

Remote role based in Spain, with a listed hiring range of €58,000–€77,000 EUR annually.

📌 Senior Software Engineer - Remote - Remote (España)
🏢 Mozilla
📍 España