JavaScript Engineer (Cybersecurity)

TL;DR

JavaScript Engineer (Cybersecurity): Developing and optimizing a high-performance client-side SDK for real-time malvertising detection and blocking with an accent on browser internals, payload size, and execution efficiency. Focus on engineering resilient SDK distribution strategies and translating threat intelligence into SDK-level detection logic.

Location: Remote (Global)

Salary: $140,000 – $220,000

Company

hirify.global provides cybersecurity for the advertising economy, protecting digital media from malvertising, scams, and compliance risks.

What you will do

• Co-own the design, development, and maintenance of the core client-side JavaScript SDK.
• Optimize SDK internals for maximum runtime performance, minimizing execution time and memory footprint.
• Develop robust SDK versioning, deployment, and distribution strategies for a large customer base.
• Translate security threat intelligence into SDK-level detection and blocking logic.
• Instrument the SDK for observability to reliably surface signals and errors to backend systems.
• Collaborate with security researchers to prototype new detection heuristics and combat evolving malvertiser methods.

Requirements

• Expert-level JavaScript (ES6+) with deep knowledge of browser internals (event loop, memory model, garbage collection).
• Proven experience building, shipping, and maintaining production-scale JavaScript SDKs or embeddable scripts.
• Ability to optimize for bundle size, parse time, and runtime efficiency.
• Proficiency with modern tooling: bundlers (Webpack, Rollup, esbuild), transpilers (Babel/SWC), and testing frameworks (Jest, Playwright).
• Deep familiarity with browser security models, including CSP and same-origin policy.
• Experience: 6+ years for Staff level, 8+ years for Senior Staff level.

Nice to have

• Experience in AdTech, including ad serving infrastructure or programmatic advertising.
• Background in security engineering, threat detection, or malware analysis.
• Experience instrumenting client-side SDKs for telemetry and observability.
• Familiarity with browser automation tools like Puppeteer or Playwright.

Culture & Benefits

• 100% virtual company with a free global co-working membership.
• Unlimited Paid Time Off and Sabbatical.
• Comprehensive health care plans (Medical, Dental, Vision) and 401(k) with automatic employer contribution.
• Stock Option Plan.
• Learning & Development budget and yearly office supply stipend.
• Enhanced and extended family leave.