Sr. Software Development Engineer (React/Typescript/Browser Extension Development)

About Zscaler Zscaler accelerates digital transformation to ensure our customers can be more agile, efficient, resilient, and secure. As an AI-forward enterprise, we are constantly pushing the envelope, leveraging the world’s largest security data lake to power our cloud-native Zero Trust Exchange platform. This innovation protects our customers from cyberattacks and data loss by securely connecting users, devices, and applications in any location. Here, impact in your role matters more than title and trust is built on results. We say, impact over activity. We seek innovators who actively use AI to amplify their impact and who thrive in an environment where we leverage intelligent systems to stay ahead of evolving threats. We believe in transparency and value constructive, honest debate—we’re focused on getting to the best ideas, faster. We build high-performing teams that can make an impact quickly and with high quality. To do this, we are building a culture of execution centered on customer obsession, collaboration, ownership, and accountability. We value high-impact, high-accountability with a sense of urgency where you’re enabled to do your best work and embrace your potential. If you’re driven by purpose, thrive on solving complex challenges, and want to be part of the team that’s helping to secure the AI age, we invite you to bring your talents to Zscaler and help shape the future of cybersecurity. Role We are looking for a Senior Software Development Engineer to join our Frontend Engineering team and help build and evolve Zero Trust Browser, our Browser Detection and Response (BDR) extension that protects users directly inside Chrome, Firefox, and Safari. This is more than standard UI work: you will build in-browser security capabilities detecting threats, enforcing enterprise policy, and analyzing content in real time across the extension's many feature modules and execution contexts. You'll turn product requirements and UI/UX designs into reliable, secure, and highly performant TypeScript that runs on millions of users' browsers without getting in their way. This is a hands-on individual-contributor role for someone with strong engineering fundamentals who wants to grow their depth in browser-platform, security, and frontend engineering. What You'll Do (Key Responsibilities) - Build Extension Features: Translate product requirements and UI/UX designs into clean, well-tested, and performant browser-extension features, spanning from user-facing UI to deep in-browser security and detection capabilities - Build Performant, Secure Tooling: Implement security-sensitive logic that runs on every page load with minimal overhead. You must care deeply about latency, memory consumption, and ensuring the browsing experience is never degraded - Write Quality, Maintainable Code: Produce highly readable, modular code that follows established patterns and conventions, while actively participating in and elevating team code reviews - Test & Debug Rigorously: Write comprehensive unit and integration tests for your work, and comfortably debug issues across complex browser contexts (background scripts, content scripts, popups, and extension pages) using browser developer tools - Collaborate Cross-Functionally: Partner closely with UI/UX designers, backend engineers, and QA to ship features end-to-end, maintaining clear communication regarding progress and blockers Who You Are (Success Profile) - You Think at Scale: You connect your day-to-day work to the larger company mission and think globally. You build solutions, processes, and architectures that are not just effective today, but are built to last and support a high-growth organization - You are Driven by Innovation: You possess a deep curiosity for how things work and are energized by solving complex technical hurdles. You believe in the power of technology to accelerate transformation and consistently hunt for more secure, scalable methods - You are a Problem-Solver: You actively seek out engineering challenges because you are energized by finding solutions, knowing that solving the hardest problems delivers the biggest business and customer impact - You are Data-Driven: You lean on data and analytics to uncover engineering truths, measure what matters, and guide informed architectural decisions replacing "I think" with "I know." - You are a Learner: You have a true growth mindset and never stop developing your technical or leadership skills. You actively seek and implement feedback to become an exceptional collaborator and teammate What We're Looking For (Minimum Qualifications) - 2–4 years of professional software development experience, with meaningful time spent building production frontend applications in TypeScript and/or JavaScript - Browser-extension development experience for Chrome, Firefox, and/or Safari. A solid working understanding of extension APIs, manifest versions (MV2 / MV3), permission models, and the separation betwe

2–4 years of professional software development experience, with meaningful time spent building production frontend applications in TypeScript and/or JavaScript. Browser-extension development experience for Chrome, Firefox, and/or Safari. A solid working understanding of extension APIs, manifest versions (MV2 / MV3), permission models, and the separation between MV2 and MV3.