Javascript Engineer (IV-V)

About this role

Confiant seeks an experienced JavaScript Engineer to own the development and optimization of their core client-side SDK that detects and blocks malvertising in real-time. This specialized role focuses on building high-performance, resilient JavaScript that executes across diverse publisher environments while translating security threat intelligence into detection logic.

What you'll do

• Co-own design, development, and maintenance of the client-side JavaScript SDK
• Optimize SDK for runtime performance, minimizing execution time and memory footprint across diverse environments
• Develop versioning, deployment, and distribution strategies for seamless updates across large customer bases
• Translate security threat intelligence into SDK-level detection and blocking logic
• Build observability instrumentation to surface signals, errors, and detection events to backend systems
• Collaborate with security researchers to prototype new detection heuristics and stay ahead of evolving threats

What they're looking for

• Expert JavaScript (ES6+) with deep browser internals knowledge
• Third-party and sandboxed JavaScript environments (iframes, cross-origin contexts)
• SDK design, shipping, and maintenance at production scale
• Performance optimization (bundle size, parse time, runtime efficiency)
• SDK distribution and versioning strategies
• Modern JavaScript tooling (bundlers, transpilers, testing frameworks)
• Production debugging in complex ad environments
• Security and malvertising threat detection principles

Benefits

• 100% virtual, work-from-home opportunities worldwide
• Optional monthly gatherings in New York City
• Quarterly on-sites in various global locations
• Small, collaborative engineering team focused on high standards
• End-to-end ownership of technical problems
• Opportunity to work on cybersecurity for the advertising industry