About Zscaler Our Engineering team built the world's largest cloud security platform from the ground up, and we keep building. With more than 100 patents and big plans for enhancing services and increasing our global footprint, the team has made us and our multitenant architecture today's cloud security leader, with more than 15 million users in 185 countries. Bring your curiosity and craftsmanship to our team of cloud architects, software engineers, security experts, and more who are enabling organizations worldwide to harness speed and agility with a cloud-first strategy.

About the Role
We are looking for a Browser Extension Engineer to join our team. This is a Hybrid (Bangalore) role, reporting to the Director, Threat Researcher in the Engineering department. Zero Trust Browser is our Browser Detection and Response (BDR) extension that lives inside Chrome, Firefox, and Safari to protect users where they actually work by detecting threats, enforcing enterprise policy, and analyzing content in real time without slowing anyone down. This is not a typical frontend role; most of the work happens beneath the UI layer in code that runs on every page a user visits across browsers we do not control and websites we have never seen. The core engineering challenges center on the browser itself: how pages load, how extension contexts communicate, how to stay quick and invisible, and how to build controls that hold up against active evasion. You will join a small, senior team as a hands-on individual contributor, owning features end to end and shaping how a large, modular codebase grows. What you’ll do (Role Expectations)
• Design and ship extension features end to end, from the detection or enforcement logic in the browser to the user-facing experience around it
• Write code that runs on every page load for millions of users, where speed, memory, and "don't break the website" are product requirements




• Think like an attacker about your own work, and build controls that are hard to bypass
• Handle the differences between Chrome, Firefox, and Safari behind clean abstractions the rest of the team can rely on
• Diagnose problems you can't reproduce locally, using telemetry and good instrumentation What We’re Looking for (Minimum Qualifications)
• Foundational understanding of AI/ML technologies and experience leveraging, securing, or positioning AI-driven solutions to optimize outcomes within your functional domain
• 5+ years of software engineering experience, with deep, hands-on TypeScript or JavaScript
• Browser-extension experience on Chrome, Firefox, or Safari: extension APIs, manifest versions, permission models, and how content scripts, background workers, and extension pages fit together
• Strong knowledge of the web platform itself, not just a framework on top of it: how pages load and execute, the DOM and its event model, iframes and cross-origin boundaries, web workers, browser storage, and security features like CSP
• A genuine mental model of JavaScript: async behavior, closures, modules, and a type system you use to prevent bugs rather than annotate them
• Comfortable building UI with any reactive library (React, Vue, Svelte, or similar) based on a deep understanding of state and rendering What Will Make You Stand Out (Preferred Qualifications)
• Proven ability to leverage AI technologies and workflows to drive measurable operational efficiency
• Published browser extensions and third-party code executing on unowned pages (e.g., analytics agents, embedded SDKs/widgets, payment or login iframes, bookmarklets, and userscripts)
• Proven experience architecting IPC-driven multi-process desktop applications, engineering AppSec solutions, building browser automation/anti-bot systems (Puppeteer, Playwright, CDP), or managing low-level DOM and custom build pipelines (esbuild, Rollup, Wasm)

📌 Browser Extension Engineer (Bengaluru)
🏢 Zscaler
📍 Bengaluru