JavaScript Engineer - Web Browser Vulnerabilities
English Required / Based in Lisbon, Portugal / Hybrid
We are seeking a skilled JavaScript 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 of malicious browser extensions.
Conduct regular code reviews and provide constructive feedback aligned with secure coding best practices.
Analyze JavaScript code to identify malicious activities and, when necessary, reverse engineer the code.
Define and implement detection rules and security patterns to identify violations at scale.
Identify emerging threat patterns and share insights to enhance team detection capabilities.
Drive innovative ideas, recommend improvements, and help design and implement automation for existing processes.
Act as a technical consultant, providing guidance, clarification, and technical grooming to team members.
Collaborate effectively with cross‑functional teams and maintain clear technical documentation.
Contribute to continuous improvement of security workflows and tooling.
You are someone who brings:
Strong hands‑on experience with JavaScript, including advanced concepts such as closures, prototypes, variable scope, hoisting, callbacks, and OOP principles.
Required hands‑on experience with HTML and CSS.
Required knowledge of JSON, AJAX, and ES6/ES7 standards.
Good understanding of Node.js and Webpack.
Experience working with front‑end frameworks or libraries such as React, Angular, or jQuery.
Strong code analysis, debugging, and reverse engineering skills, particularly in JavaScript applications.
Ability to analyze JavaScript code and identify malicious activities effectively.
Good communication skills and the ability to work as a collaborative team player.
Added Advantages (Nice to Have):
Cybersecurity experience or strong security knowledge.
Familiarity with DAST and SAST methodologies.
Knowledge of cybersecurity open‑source tools such as Burp Suite, Nmap, or similar tools.
Understanding of obfuscation and de‑obfuscation techniques.
Experience writing technical and security assessment reports.
私たちについて:
コグニザント(NASDAQ: CTSH)は、AI builderおよびテクノロジーサービスプロバイダとして、AI投資を企業価値へとつなげるフルスタックのAIソリューションを提供しています。業界、業務プロセス、エンジニアリングに関する深い専門性を強みに、各企業固有のコンテキストをテクノロジーシステムに組み込み、人の力を最大限に引き出すとともに、具体的な成果の創出と、急速に変化する世界におけるグローバル企業の競争力維持を支援します。詳しくは、当社ウェブサイト www.cognizant.com をご覧ください。
雇用に関する追加情報
本募集に記載されている報酬情報は、掲載日時点で正確なものです。Cognizantは、適用される法令に従い、いつでも本情報を変更する権利を留保します。
応募者は、対面またはビデオ会議による面接への参加を求められる場合があります。また、各面接の際に、現在有効な州政府または政府発行の身分証明書の提示を求められる場合があります。
Cognizantは機会均等雇用主です。応募および選考において、人種、肌の色、性別、宗教、信条、性的指向、性自認、国籍、障がい、遺伝情報、妊娠、退役軍人の地位、その他連邦法・州法・地方自治体の法律により保護されるいかなる特性に基づく差別も行いません。







