Frontend Engineer (Web Security)

TL;DR

Frontend Engineer (Web Security): Analyze browser extension code using static and dynamic analysis techniques to identify security violations and malicious behavior, with an accent on JavaScript-based front-end technologies and code reverse engineering. Focus on reviewing source code for actual versus declared functionality, defining detection rules, and auditing internal tools for gaps.

Location: Lisbon based/hybrid

Company

One of the world's leading professional services companies, transforming clients' business, operating, and technology models for the digital era.

What you will do

• Analyze browser extension code with static and dynamic techniques to detect security violations and malicious behavior.
• Perform reverse engineering, debugging, and code reviews focused on JavaScript front-end technologies.
• Identify vulnerabilities, document findings, and recommend remediation actions.
• Support takedown of malicious extensions and audit internal review tools.
• Define detection rules, share threat insights, and contribute to process improvements and automation.
• Act as technical consultant, conduct code reviews, and collaborate with cross-functional teams.

Requirements

• Strong hands-on experience with JavaScript, including advanced concepts like closures, prototypes, variable scope, hoisting, callbacks, and OOP principles.
• Proficiency in HTML and CSS.
• Solid experience in code review to assess real behavior and intent.
• Experience with database queries such as SQL.
• Strong analytical mindset with curiosity and critical thinking.

Nice to have

• Knowledge of web application and cybersecurity fundamentals, vulnerability assessment.
• Familiarity with browser extensions lifecycle, malware behaviors, obfuscation techniques.
• Experience with cybersecurity tools like Burp Suite, Nmap; DAST/SAST methodologies.
• Node.js, Webpack, front-end frameworks (React, Angular, jQuery).
• Writing technical and security assessment reports.

Culture & Benefits

• High caliber, energetic, collaborative, and inclusive workplace.
• Global community with over 300,000 associates worldwide.
• Foster innovation and support career path development.
• Commitment to people, clients, company, communities, and climate.