Senior Web Browser Researcher

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Web Browser Researcher based in Spain.
Join a fully remote, globally distributed team developing advanced device intelligence and fraud-detection technology. As a Senior Web Browser Researcher, you will investigate browser behavior, discover novel identification techniques, and improve the accuracy and stability of core products. You will lead research from initial hypothesis through validation and engineering implementation, turning complex technical discoveries into measurable product improvements. Working at the intersection of JavaScript, browser internals, web security, and networking, you will tackle open-ended challenges that require rigorous experimentation and reverse engineering. You will also develop automated research tools, anticipate browser platform changes, and collaborate closely with product and engineering teams. This role offers the opportunity to shape cutting-edge technology, mentor peers, and contribute to the broader research community.
Accountabilities:
Research novel device-identification, visitor-identification, Smart Signals, and bot-detection techniques across modern web browsers, working effectively with ambiguous or evolving requirements.
Evaluate research findings against real-world constraints, including performance budgets, execution contexts, same-site behavior, proxy implications, and interactions with existing signals.
Design and conduct experiments, analyze supporting data, and deliver clear recommendations with estimated impact, false-positive and false-negative rates, limitations, and trade-offs.
Stay involved throughout implementation by reviewing engineering changes, clarifying research objectives, answering technical questions, and advising on edge cases.
Build and maintain automated research tooling, including observers, fuzzers, and scrapers, to discover new signals and detect browser platform changes.
Monitor browser beta, canary, and developer channels, as well as technical specifications and RFC discussions, to anticipate changes and assess their potential product impact.
Produce structured research outputs, including internal reports, technical articles, proofs of concept, experimental signal implementations, and supporting analyses.
Collaborate with product and engineering partners to translate complex technical findings into actionable development priorities.
Contribute to the research team's growth through mentorship, peer review, knowledge sharing, and public technical thought leadership.
Requirements:
Deep understanding of web platform fundamentals, browser internals, and web security concepts.
Strong proficiency in JavaScript and the ability to read, understand, and navigate code written in multiple programming languages.
Solid knowledge of web networking fundamentals.
Demonstrated ability to uncover and explain undocumented behavior in web technologies, APIs, and protocols through testing, debugging, and reverse engineering.
Experience independently driving research from an initial idea through experimentation, validation, and actionable recommendations.
Ability to design and execute experiments using real-world traffic and analyze large-scale datasets to validate findings.
Recognized depth in at least one relevant area, such as reverse engineering, network research, or device identification, alongside working knowledge of adjacent fields.
Strong written and verbal communication skills, including the ability to explain research outcomes, expected impact, limitations, and trade-offs to engineering and product teams.
Preferred Qualifications:
Experience developing research and automation tools, such as scrapers, fuzzers, and observers.
History of reporting bugs or submitting technical issues to Chromium, Firefox, or WebKit bug trackers.
Experience or interest in backend development, particularly Go.
Familiarity with anti-fingerprinting techniques and their implementation across browsers and browser extensions.
A public research portfolio, such as conference presentations, technical blog posts, CVEs, or open-source contributions.
Interest in mentoring colleagues, conducting peer reviews, and sharing research with the wider technical community.
Benefits:
Competitive salary:
$174,000–$235,000 annually for US-based employees, depending on location, experience, and expertise.
Location-based compensation:
Example ranges include $204,000–$235,000 in New York City and $174,000–$200,000 in Chicago.
Fully remote work:
Join a globally distributed, remote-first team, with the ability to work from approved locations where employment is permitted.
Meaningful technical impact:
Help shape advanced device-identification and fraud-detection capabilities used in real-world applications.
Research and innovation:
Work on challenging, open-ended problems involving browser internals, web security, and emerging identification techniques.
Professional growth:
Opportunities to mentor peers, participate in technical reviews, and contribute to public research and thought leadership.
Inclusive work environment:
Join a team committed to respecting diverse experiences, perspectives, and cultural backgrounds.
Work authorization:
Visa sponsorship is not provided, and candidates must be authorized to work from their home location. Certain countries are excluded for regulatory and security reasons.
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