Senior JavaScript Security Researcher

Your mission

About the Job

Title:

Senior JavaScript Security Researcher

Position:
Full-time | 40 hours per week

Location:

Amsterdam, Netherlands | Work From home (2–3 days per week in the office)

Salary Range: €80,000–100,000 annually

As a Senior JavaScript Security Researcher you’ll explore new browser capabilities, uncover detection methods, and turn cutting‑edge research into real‑world protection used at a global scale. You will maintain and enhance our FRS web SDKs, drive new detection capabilities, and work closely with Threat Analysts and Product teams to improve fraud detection.

• Maintain and evolve our FRS web SDKs.
• Develop new detection capabilities.
• Detect and investigate fraud patterns and trends.
• Collaborate with Threat Analysts and Product teams.
• Explore and experiment with new and upcoming browser APIs.
• Research how these APIs can be used to create novel detection mechanisms.

• 12‑month contract with potential extension to permanent.
• Competitive salary aligned with experience, €80,000–€100,000 annually.
• 25 holidays per year + 8% holiday allowance.
• Pension scheme.
• Flexible remote/hybrid work and working hours.
• Opportunities for professional growth and impact.

Skills and qualifications

• 8+ years of experience in JavaScript and/or framework development.
• Experience with browser APIs for mouse, keystroke, scroll dynamics, etc.
• Proficient with Git and open‑source development workflows.
• Strong debugging and problem‑solving skills.
• Knowledge of Docker is a plus.
• Excellent written English; clear documentation.
• Team player with strong communication skills.

Creativity & Innovation

• Generate and implement creative, innovative solutions to complex problems.

Problem‑Solving

• Communicate solutions clearly.
• Adaptability and flexibility within a scale‑up environment.

Communication & Interpersonal Skills

• Explain technical concepts to diverse audiences.
• Collaborate effectively and show empathy.

Continuous Improvement

• Seek opportunities to enhance workplace practices and product quality.
• Committed to ongoing learning and development.

Interested? We encourage motivated and passionate candidates to apply. The position is open until filled.