A successful Cyber SaaS company is looking for a Senior JavaScript Engineer to build advanced browser-based capabilities at the core of its security product.
This role is designed for engineers who live and breathe vanilla JavaScript and enjoy working deep in browser logic, performance, security, and low-level web behavior. You will partner closely with Security Researchers and Product Managers to turn new attack insights into production-ready JavaScript capabilities.
Key Responsibilities
• Design and implement advanced signal-collection logic in pure JavaScript
• Work with browser APIs, device characteristics, and user-behavior signals
• Lead projects end to end, from architecture and development to deployment and monitoring
• Translate security research into practical detection and prevention capabilities
• Optimize code for performance, stability, security, and cross-browser compatibility
• Collaborate with Product, Research, Security, and Engineering teams
Required Experience
• 4+ years of hands-on software development experience
• Deep expertise in vanilla JavaScript and browser internals
• Strong knowledge of web security, browser APIs, and cross-platform behavior
• Experience owning complex technical projects from design to production
• Background in a typed backend language such as Go or Java
• Strong communication, collaboration, and problem-solving skills
Strong Advantages
• Experience in AdTech, cybersecurity, bot mitigation, or fraud prevention
• Familiarity with CDNs and large-scale JavaScript deployment
• A research-oriented mindset and strong interest in attacker behavior
• Experience building high-performance client-side systems