Build and maintain our browser-side TypeScript/JavaScript agent used for device identification, bot detection, and risk assessment
Engineer for stealth, resilience, and performance—minimizing footprint, resisting detection, and maintaining compatibility across browsers
Optimize for both code size and execution speed in complex, adversarial environments
Stay ahead of browser changes, plugin behaviors, and fingerprinting techniques
Collaborate with backend, security, and data science teams to align signal capture with detection logic
Write comprehensive tests and contribute to CI pipelines that ensure functionality across a wide range of platforms and devices
Contribute to a widely-used open-source project with 24K+ GitHub stars and 25B+ monthly usages

3-5 years of JavaScript and TypeScript experience, especially in browser environments
Deep understanding of browser APIs, DOM behavior, timing attacks, and anti-debugging techniques
Experience building libraries or SDKs, especially for production or developer-facing use cases
Strong frontend experience (~80%), with backend familiarity (~20%)
Proficiency with build tools like Vite, Webpack, Rollup, Esbuild, including code obfuscation and minification
Experience with modern testing frameworks such as Vitest, Jasmine, Jest, or similar
Familiarity with security principles, privacy best practices, and adversarial engineering
Comfortable working in fast-paced environments without rigid specifications
Strong sense of ownership and autonomy; you enjoy working independently and solving hard technical problems
Clear written and verbal communication skills in English

Senior Software Engineer – Javascript/Typescript

Key skills