Senior Web Security Engineer, Browser Platform

WHO WE ARE Hi, we're DuckDuckGo, the online protection company and remote-first team of 300+ on a mission to raise the standard of trust online. Founded in 2008 and profitable since 2014, annual revenue now exceeds $100m USD and millions use our browser on on Mac https://spreadprivacy.com/introducing-duckduckgo-for-mac/, Windows https://spreadprivacy.com/windows-browser-open-beta/, iOS https://spreadprivacy.com/duckduckgo-privacy-browser-ios14/, and Android https://spreadprivacy.com/introducing-app-tracking-protection/, our search engine https://duckduckgo.com/, and the DuckDuckGo subscription https://duckduckgo.com/pro. We also offer private, useful, and optional AI, including Duck.ai https://duck.ai/, which lets you chat privately with ChatGPT, Claude, and other AIs, all in one place. Our culture https://duckduckgo.com/how-we-work of trust, inclusivity, and empowered project management underpins everything we do, where each team member takes full ownership of their projects, from scoping and execution to postmortem. If you're seeking end-to-end ownership of your work, you've come to the right place! YOUR TEAM AND ROLE Working on the Security Functional Team, you'll play a pivotal role in ensuring our security capabilities keep pace with our rapid product development, including our expanding AI offerings like Duck.ai and agentic browsing, directly protecting our users across all our products. You'll also maintain incident detection and response capabilities for the company, and work on related projects. Recent projects include: - Browser and sync security audits - SERP security mitigations - Agentic browser hardening As a Senior Web Security Engineer, Browser Platform, you'll harden our agentic browsing and DuckAI experiences against emerging threats (like prompt injection), conduct browser and sync security audits (special pages, DuckAI integrations, password manager, etc.), execute on SERP security mitigations (XSS prevention, tooling development to help engineers write safer code), build and maintain harnesses that get security fixes out automatically, manage application security scanning infrastructure setup, deliver on internal red-team operations (simulated attack scenarios), support security triage, and more! ABOUT YOU - 7+ years of experience in web or application security (performing security assessments, vulnerability research, penetration testing, or secure code review) - Recent experience creating security focused agentic harnesses - Experience influencing large feature designs to have security baked in from the start - Advanced programming or scripting experience with JavaScript. Any additional experience with our stack is a bonus: Swift/Kotlin/C#/JavaScript (native apps) or JavaScript/Perl/Go (search). - Experience with at least one WebView technology (WebKit, WebView2, Chromium WebView, etc.) and understanding of browser security models (SOP, CSP, CORS, SameSite cookies) - Hands-on experience identifying and exploiting web vulnerabilities (XSS, CSRF, injection attacks, authorization flaws, etc.) - Familiarity with security testing tools and frameworks - Experience partnering and collaborating with Product Engineers, advising on security matters and helping teams ship secure code faster - Experience shaping how an organisation thinks about security - driving best practices, improving processes, and raising the bar across teams COMPENSATION $178,500 USD annually and stock options. Compensation is transparent across the organization, and all team members within the same professional level and global region receive the same compensation.   Eligibility for company-sponsored health benefits is limited to team members based in the United States. This program does not extend to team members located in other countries, such as Canada or the UK.   Our Team Member Support Guide https://duckduckgo.com/assets/hiring/team_support_guide.pdf explains how we prioritize your wellbeing including paid parental leave, office setup, and co-working allowances. HIRING PROCESS Hiring works best when it's a two-way street. Learn how we help you get to know DuckDuckGo, envision your future role here, and find out more about how we hire https://duckduckgo.com/how-we-hire. DIVERSITY, EQUITY AND INCLUSION DuckDuckGo provides equal work opportunities to all team members and applicants, and it prohibits discrimination and harassment of any type on the basis of race, color, ethnicity, caste, religion, age, sex (including pregnancy), national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by our policies or federal, state, or local laws. We want to ensure that our hiring process is accessible. If you need reasonable accommodation for any part of the application process because of a medical condition or disability, please send an email to careers@duckduckgo.com to let us know the nature of your request. PLEASE NOTE THAT: - You’ll be required to attend meetings on camera via video conferencing - Expect to travel at least two times a year: once for our all-hands meetup and again for a team retreat (each around 4-5 days). While extenuating circumstances may impact attendance, everyone is strongly encouraged to attend. - While we offer a flexible work arrangement with no core hours, expect an average full-time commitment of 40 hours per week. - A successful candidate must pass a background check as a condition of joining the team. - By applying for this role, you confirm that all information submitted is accurate and complete. You further acknowledge that providing false or fraudulent information during the application process is cause for denial of an offer, revocation of any existing offer, or other adverse action, up to and including termination after the start of your commencement of work. Disclosure Statement: Use of AI in Hiring Process As part of our commitment to enhancing our recruitment process, we utilize artificial intelligence (AI) technology to assist in reviewing and summarizing job applications and test projects, including those tools integrated into our recruitment vendor platforms. We use AI to flag potentially fraudulent applications, analyze and summarize applicants’ experience, interviews, and project performance, and help streamline our selection process. Key Principles: - Data Privacy: All information provided in your application will be handled in accordance with our Recruiting Privacy Policy https://duckduckgo.com/static-assets/files/pages/careers/DuckDuckGo-Recruiting-Privacy-Policy-effective-September-30-2025.pdf. We ensure that your personal information is protected and used solely for recruitment purposes. - Human Oversight and Accountability: The AI technology is designed to support our hiring team by providing insights and summaries of applications and evaluations of test projects against scoring rubrics. All final evaluations and hiring decisions, however, will be made by our hiring team, who will consider the AI's input alongside other factors. - Transparency: We believe in transparency regarding our hiring practices. If you have any questions about how AI is used in our recruitment process, please feel free to reach out to us. By submitting your application, you acknowledge and consent to the use of AI technology in our review process. If you would like to request an alternative selection process, please contact us as at careers@duckduckgo.com. Thank you for your interest in joining DuckDuckGo! #LI-DNI