Senior Web Security Engineer, Browser Platform

📋 Job Overview

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 Mac, Windows, iOS, and Android, our search engine, and the DuckDuckGo subscription. We also offer private, useful, and optional AI, including Duck.ai, which lets you chat privately with ChatGPT, Claude, and other AIs, all in one place. Our culture 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!

🏢 About DuckDuckGo

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

🎯 The Role

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!

✅ Key Responsibilities

• 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

📌 Required Qualifications

• 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

⭐ Desirable Experience

• Experience 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

🎁 Benefits

$178,500 USD annually and stock options. 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 explains how we prioritize your wellbeing including paid parental leave, office setup, and co-working allowances.

🛂 Visa & Eligibility

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.