Senior Software Engineer, Firefox Security

🕒 June 25

🇪🇸 Spain – Remote

💵 €58k - €77k / year

⏰ Full Time

🟠 Senior

🧑‍💻 Full-stack Engineer

👻 Ghost score 10%

What it means: how likely this posting is sitting open without active hiring.How to read it: 60% or higher means we think this is a ghost. Lower scores are less of a worry.How we score it: age, reposts, open roles vs team size, how fast jobs close, and whether pay is listed.Fine print: an estimate from public data, not a judgment of the company. Real jobs can score high, so treat it as a hint, not a fact.

Apply Now

Find Similar Remote Jobs

Set Up Email Alert For New Jobs

📊 Check your resume score for this job

Improve your chances of getting an interview by checking your resume score before you apply.

Upload Resume

Mozilla

WebsiteLinkedInAll Job Openings

501 - 1000 employees

Founded 1998

👥 B2C

🔒 Cybersecurity

B2C • Cybersecurity • Software

Mozilla is a non-profit organization dedicated to promoting an open and accessible internet. They are the makers of the popular Firefox browser, which emphasizes user privacy, speed, and control. Mozilla also offers a range of products that focus on internet security and privacy, including Mozilla VPN, Firefox Relay, and Mozilla Monitor. Additionally, the organization is involved in open-source projects, AI innovation, and advocating for digital rights. Mozilla aims to empower users with trustworthy technology and policies that protect privacy, support open-source AI development, and foster accountability for tech companies.

📋 Description

• Advance Firefox's security architecture and cryptography stack: Contribute to improvements in Firefox's core security systems, with a focus on cryptographic protocols, WebPKI, and security-sensitive web APIs. Help implement and maintain security features that support the evolution of public key infrastructure on the web. • Design and implement web platform security features: Develop and ship web platform features in collaboration with teammates and the broader web community. Contribute to standards-based, secure, and interoperable implementations across Firefox. • Improve browser reliability, performance, and resource efficiency: Investigate and resolve issues impacting stability, correctness, and performance. Analyze and improve memory usage and efficiency within a complex, multi-threaded browser environment. • Collaborate on security initiatives: Partner with engineers across teams to identify, prioritize, and address security issues. Participate in debugging, root cause analysis, and implementation of effective long-term solutions. • Contribute to technical design and planning: Participate in technical discussions, design reviews, and project planning for security-related initiatives. Help evaluate tradeoffs and contribute to engineering decisions within your area of work.

🎯 Requirements

• Strong software engineering and security fundamentals: Experience in software engineering, with proficiency in C/C++ and a solid understanding of security principles, including cryptographic protocols and implementations. • Experience building and maintaining complex software systems: Ability to contribute to the design, implementation, testing, and maintenance of software in large-scale or security-sensitive environments. • Strong debugging and problem-solving skills: Expertise in diagnosing and resolving issues in multi-threaded, cross-platform native applications, including performance and memory-related challenges. • Collaborative and effective communicator: Ability to work effectively with distributed teams, communicate technical concepts clearly, and collaborate constructively to solve problems. • Growth mindset and willingness to learn: Demonstrated curiosity and desire to deepen expertise in browser security, cryptography, and systems programming while continuously improving engineering skills. • Web platform and modern systems experience: Familiarity with web technologies and interest or experience in Rust. Comfortable working within large, complex, multi-language codebases.

🏖️ Benefits

• Generous performance-based bonus plans to all eligible employees - we share in our success as one team • Rich medical, dental, and vision coverage • Generous retirement contributions with 100% immediate vesting (regardless of whether you contribute) • Quarterly all-company wellness days where everyone takes a pause together • Country specific holidays plus a day off for your birthday • One-time home office stipend • Annual professional development budget • Quarterly well-being stipend • Considerable paid parental leave • Employee referral bonus program • Other benefits (life/AD&D, disability, EAP, etc. - varies by country)