JavaScript Security Engineer - Web Browser Vulnerabilities

English Required / Based in Lisbon, Portugal / Hybrid

We are seeking a skilled JavaScript Security Engineer with a strong background in web technologies and cybersecurity to analyze, reverse engineer, and secure browser‑based applications, with a particular focus on web extensions. This role involves identifying malicious behaviors, conducting security assessments, and driving automation and process improvements within the security analysis lifecycle.

Key Responsibilities

• Analyze web extension code using static and dynamic analysis techniques to detect security violations and malicious behavior.
• Perform JavaScript reverse engineering and debugging to understand complex or obfuscated codebases.
• Identify, document, and report security vulnerabilities, including root‑cause analysis and recommended remediation steps.
• Support the takedown and investigation...