Jobs / United States / mozilla
Senior Software Engineer, Firefox Security
mozilla · 🇺🇸 Location unlisted
Sponsorship verdict
Sponsorship possible
One solid signal, not two — worth applying, and worth asking about sponsorship early.
- Employer is on a government sponsor recordThe US Department of Labor certified 2 H-1B/E-3 labor condition applications for this employer between Oct 2025 and Jun 2026 (latest Jun 2026) — the step every H-1B hire needs first. Source: LCA disclosure data (US Department of Labor (OFLC)).
- The posting doesn’t mention sponsorshipSilence isn’t a refusal — ask the recruiter before investing much time.
- No salary bar for this routeH-1B has no fixed salary bar: the employer must pay at least the prevailing wage for the role and area. Cap-subject employers enter a lottery weighted by wage level. Source: https://www.federalregister.gov/documents/2025/12/29/2025-23853/weighted-selection-process-for-registrants-and-petitioners-seeking-to-file-cap-subject-h-1b, rules effective 2026-02-27.
- What mozilla paid sponsored hires in similar roles1 certified filing for “Senior Director of Machine Learning, Firefox” (Computer and Information Systems Managers) in WA: $413k–$413k, median $413k. Most were filed at wage level IV (100%) — 4 lottery entries, ≈61% projected selection odds for cap-subject employers. Source: US Department of Labor LCA disclosure data (Oct 2025 – Jun 2026).
- Confirmed live todayWhen a source last listed this job as open.
US H-1B: cap-subject employers enter a lottery weighted by wage level — Level I gets 1 entry, Level IV gets 4 (DHS projected selection odds ≈15% at Level I to ≈61% at Level IV). Universities and non-profit research employers are cap-exempt. The $100,000 fee for new petitions from abroad is currently blocked by a court order (appeal pending).
A verdict summarises public evidence; it is not legal advice and never a guarantee — the employer and the immigration authority decide. Sign in to factor in where you can already work.
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Sponsor Radar — mozilla
The US Department of Labor certified 2 H-1B/E-3 labor condition applications for this employer between Oct 2025 and Jun 2026 (latest Jun 2026) — the step every H-1B hire needs first. Source: LCA disclosure data (US Department of Labor (OFLC)).
Past sponsorship or register membership never guarantees sponsorship for this vacancy or for you. Full Sponsor Radar for mozilla →
About the role
Why Mozilla? Mozilla Corporation is the non-profit-backed technology company that has shaped the internet for the better over the last 25 years. We make pioneering brands like Firefox, the privacy-minded web browser. Now, with more than 225 million people around the world using our products each month, we’re shaping the next 25 years of technology and helping to reclaim an internet built for people, not companies. Our work focuses on diverse areas including AI, social media, security and more. And we’re doing this while never losing our focus on our core mission – to make the internet better for people. The Mozilla Corporation is wholly owned by the non-profit 501(c) Mozilla Foundation. This means we aren’t beholden to any shareholders — only to our mission. Along with thousands of volunteer contributors and collaborators all over the world, Mozillians design, build and distribute open-source software that enables people to enjoy the internet on their terms. What you’ll do: • Design, build and implement security and hardening features for enterprise users: Design, implement, test, and ship cutting-edge security features that strengthen Firefox’s security posture. • Advance Firefox’s security architecture across multiple operating systems: Contribute to and drive cutting-edge improvements to Firefox’s core security posture, by building privilege isolation and moving trust boundaries or Strengthen Firefox’s security architecture: Improve Firefox’s core security mechanisms including cryptographic protocols, WebPKI, and security-sensitive web APIs. • Contribute to our security initiatives: Work across teams to investigate security issues, identify root causes, and deliver robust, maintainable fixes. • Improve browser reliability and performance: Diagnose and resolve issues affecting stability, correctness, performance, and memory usage in a complex, multithreaded environment. What you’ll bring: • Systems programming experience and security knowledge: 3+ years of experience in low-level software engineering, strong proficiency in C and/or C++, and a solid understanding of security fundamentals. • Debugging and problem-solving skills: Experience diagnosing and resolving issues in multithreaded, cross-platform native applications, including memory and performance challenges. • Web platform and modern systems experience: Familiarity with web technologies (HTML, CSS, JavaScript) and interest or experience in Rust; ability to work effectively within large, complex, multi-language codebases. • Effective collaboration and communication: Experience working with distributed teams and communicating technical ideas clearly in writing and conversation. What you’ll get: • Generous performance-based bonus plans to all eligible employees - we share in our success as one team • 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) About Mozilla Mozilla exists to build the Internet as a public resource accessible to all because we believe that open and free is better than closed and controlled. When you work at Mozilla, you give yourself a chance to make a difference in the lives of Web users everywhere. And you give us a chance to make a difference in your life every single day. Join us to work on the Web as the platform and help create more opportunity and innovation for everyone online. Commitment to div