Senior Software Engineer - Javascript/Typescript

Role overview

Senior Software Engineer (JavaScript/TypeScript) to build browser-side engineering that powers device identification, bot detection, and risk assessment. You’ll work on performance-critical, tamper-resistant SDKs and CDN integrations running in hostile, security-constrained browser environments.

What you’ll do

• Build and maintain a browser-side TypeScript/JavaScript agent for device identification, bot detection, and risk assessment
• Engineer for stealth, resilience, and performance (minimize footprint, resist detection, maintain cross-browser compatibility)
• Optimize for both code size and execution speed in adversarial conditions
• 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 improve CI pipelines across platforms and devices
• Contribute to a widely adopted open-source project used at massive scale

What you bring

• 3–5 years of experience with JavaScript and TypeScript, especially in browser environments
• Deep understanding of browser APIs, DOM behavior, timing attacks, and anti-debugging techniques
• Experience building libraries/SDKs for production or developer-facing use cases
• Strong frontend focus (~80%) with backend familiarity (~20%)
• Proficiency with build tooling (Vite, Webpack, Rollup, Esbuild), including obfuscation and minification
• Experience with modern testing frameworks (Vitest, Jasmine, Jest, or similar)
• Familiarity with security principles, privacy best practices, and adversarial engineering
• Comfort working in fast-paced environments and without rigid specs
• Strong ownership, autonomy, and clear English communication

Nice to have

• Experience in complex domains such as media, gamedev, or security