Senior Software Engineer (Browser Extension)

About the Role Cyberhaven is redefining data security by understanding how data flows across organizations. Our browser extension is a critical component of this vision, enabling visibility and control at the point where users interact with web applications. We’re looking for an experienced engineer to help build and enhance our extension, ensuring it’s secure, performant, and deeply integrated with our platform. You’ll join our Browser Extension team and collaborate closely with both the endpoint agent and backend teams to deliver a seamless experience across devices and environments. What You’ll Do Design, build, and maintain a robust browser extension for Chrome, Edge, and other major browsers using Manifest V3 and modern APIs. Implement features that securely interact with web content and backend services, ensuring compliance with security best practices. Optimize performance and reliability across diverse environments and user workflows. Work closely with the endpoint agent and backend teams to ensure tight integration and consistent functionality across endpoints and services. Stay ahead of evolving browser APIs, security standards, and extension ecosystem changes. Participate in code reviews, testing, and continuous improvement of development processes. Who You Are You have extensive experience in software engineering: coding, testing, debugging, and automating complex TypeScript/JavasScript applications You're comfortable digging into third-party web applications you don't control — inspecting network traffic, DOM structure, and client-side code to understand how a page works You have the ability to learn new technologies quickly and are eager to do so — especially as browser extension platforms and manifest specs continue to evolve You focus on correctness, performance, and reliability of background processes You have excellent communication skills, You are able to work self-sufficiently at times with minimal direction. You can coordinate work effectively between yourself and developers working on non-browser platforms. Bonus points You have hands-on experience building or maintaining browser extensions (Chrome/Chromium Manifest V3 experience strongly preferred; Firefox/Edge a plus), including background scripts, content scripts, and extension messaging patterns You understand the security model of browser extensions - permissions, content security policy, isolated worlds, and safe communication between contexts You have experience building cybersecurity products or features, such as DLP (Data Loss Prevention), DSPM (Data Security Posture Management), or similar security/compliance tooling Joining Cyberhaven means joining the team building Data Security for the Agentic Enterprise. Traditional tools fall short. Cyberhaven traces the full lifecycle of your data, adapting protection to changing context, so protection moves with the way people actually work, not against it. AI Changed Work. We Protect It. Backed by $250M from leading investors like Khosla and Redpoint, our team includes leaders who built industry-defining technologies at CrowdStrike, Palo Alto Networks, Meta, Google, and more. This role lets you shape the future of data security, working alongside people driven to protect workflows, not just data, for customers who cannot afford to slow down to stay safe. AI Tools Disclosure: As part of Cyberhaven's hiring process, we use recruiting tools that include AI-powered features to help with tasks like scheduling, note-taking, workflow automation, and other recruiting activities ("AI Tools"). The AI Tools may process information you provide during the application and interview process. When AI-assisted interview note taking is used, candidates are notified in advance and have the option to opt out of the AI-assisted interview note taking. Cyberhaven is committed to creating a diverse environment and is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, gender, gender identity or expression, sexual orientation, national origin, genetics, disability, age, or veteran status.