Team Lead - JS Agent

Know what really happens under the hood of a browser and enjoy helping others navigate it too?

Can you reason about the JavaScript event loop, browser rendering pipeline, and performance tradeoffs instinctively? Have you built or significantly shaped complex browser-side systems that had to survive at massive scale? Do you enjoy defining what should be built just as much as how it should be built and then diving into the code to make it real?

The Team Lead - JS Agent role sits at the intersection of technical leadership and hands-on engineering. You’ll help shape our roadmap, guide architectural decisions, and maintain a healthy, prioritized backlog while still spending your remaining time writing, reviewing, and shipping production code.

This isn’t a traditional management role, and it’s not a standard JavaScript job either. We’re building world-class systems that run in one of the most constrained and adversarial environments there is: the browser.

We’re hiring a Team Lead to lead the evolution of our browser-side JavaScript agent, CDN integrations, and performance-critical SDKs used by millions of users every day. You’ll be responsible for setting technical direction, unblocking complex problems, and ensuring our codebase remains fast, resilient, and maintainable while staying deeply embedded in the implementation.

If you want to push the boundaries of what’s possible in the browser and help steer the direction of a highly technical product, we’d love to hear from you. Before applying, feel free to explore our open-source projects to see if you can picture yourself here.

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What You’ll Do

• Act as the technical owner for our browser-side TypeScript/JavaScript platform, including our core agent, SDKs, and CDN integrations
• Partner with product, security, and engineering stakeholders to help define the technical roadmap and translate goals into a clear, actionable backlog
• Lead architectural design and make high-impact technical decisions, balancing performance, security, and long-term maintainability
• Spend a significant portion of your time writing, reviewing, and shipping production code in performance-critical, adversarial browser environments
• Engineer for stealth, resilience, and efficiency; minimizing footprint, resisting detection, and maintaining compatibility across browsers and devices
• Stay ahead of browser changes, plugin behaviors, and evolving fingerprinting and anti-debugging techniques
• Set quality standards through code reviews, testing strategy, and CI improvements, ensuring reliability at massive scale
• Collaborate closely with backend, data science, and security teams to align signal collection, detection logic, and system constraints
• Mentor senior and mid-level engineers through technical guidance, design reviews, and knowledge sharing (without formal people management responsibilities)
• Contribute to and help steward a widely-used open-source project with 24K+ GitHub stars and 25B+ monthly usages
• A desire to transition from an individual contributor to an engineering management role.

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What You Bring

• 5-7+ years of professional JavaScript and TypeScript experience, with deep expertise in browser environments
• Strong technical leadership skills: you’ve guided architecture, influenced roadmaps, or acted as a go-to technical authority on complex systems
• Deep understanding of browser internals, APIs, DOM behavior, timing attacks, and anti-debugging techniques
• Experience building and maintaining production-grade libraries, SDKs, or platforms used by other developers
• Comfort operating across abstraction levels: high-level system design one moment, low-level performance tuning the next
• Strong frontend expertise (~70–80%), with enough backend familiarity (~20–30%) to reason about end-to-end systems
• Proficiency with build and bundling tools such as Webpack, Rollup, or Esbuild, including minification and obfuscation strategies
• Experience with modern testing frameworks (Jest, Jasmine, or similar) and CI pipelines
• Solid grounding in security principles, privacy considerations, and adversarial engineering
• Ability to work effectively in fast-moving environments where requirements evolve and tradeoffs must be made explicitly
• Clear, thoughtful written and verbal communication skills in English

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Nice to Have

• Experience leading or significantly shaping technically complex browser products (e.g., Google Docs, Figma, Miro, browser-based games, media platforms, or security tooling)
• Meaningful contributions to open-source projects, particularly in the JavaScript or TypeScript ecosystem
• Experience with WebAssembly, browser extensions, or advanced debugging techniques
• Familiarity with AWS services such as Lambda, CloudFront, and DynamoDB
• Browser automation, scraping, or reverse-engineering experience

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For US-based employees, the cash compensation range for this role is $178,000 – $205,000. We set standard ranges for all US roles based on function, level, and geographic location, benchmarked against similar stage growth companies. To comply with local legislation and provide greater transparency to candidates, we share salary ranges on all job postings regardless of desired hiring location. However, these ranges are specific to the hiring location and may differ within or outside the US. Final offer amounts are determined by multiple factors, including geographic location as well as candidate experience and expertise, and may vary from the amounts listed above.