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