Join a global technology and e-commerce leader in Tokyo as an IT Security Engineer, helping protect a large-scale digital ecosystem and millions of users from phishing, fraud, and emerging cyber threats.

Working within a specialised Cyber Security Defense and Anti-Cyber Crime team, you will combine cybersecurity engineering, threat intelligence, incident response, and software development to identify malicious activity and build automated countermeasures.

This role offers hands-on exposure to Python, SQL, OSINT, threat intelligence, CSIRT operations, phishing analysis, and security automation. You will investigate real-world cybercrime, analyse complex datasets, research emerging threats across the open and dark web, and develop tools that strengthen anti-fraud capabilities in Japan and globally.
Key Responsibilities

• Design, develop, and continuously improve anti-fraud and cybercrime countermeasures through collaboration with internal security teams and external partners.
• Build and maintain automated analysis tools and security applications using Python and data-driven techniques to identify and disrupt phishing and fraudulent campaigns.
• Conduct OSINT, dark web, and closed-media research to identify emerging cyber threats, attack techniques, and fraud trends.
• Perform CSIRT incident response for active phishing websites, fraudulent campaigns, and other cybersecurity incidents.
• Analyse complex datasets using SQL and investigative techniques to identify malicious activity and support cybercrime investigations.
• Apply knowledge of HTTP, TLS, SMTP, and DNS to investigate network and web-based fraud techniques.
• Support collaboration with relevant external organisations and provide technical analysis that can contribute to law enforcement actions and criminal investigations.
• Contribute cybersecurity engineering, threat research, and defensive expertise to the dedicated Anti-Cyber Crime function.
• Identify opportunities to automate repetitive investigation and response processes, improving the speed and effectiveness of cyber defence.

Required Skills and Qualifications Experience:

• 3+ years of technical or engineering experience in cybersecurity, cybercrime defence, security engineering, or a related field.
• 3+ years of hands-on Python programming experience, including development of tools, applications, or automation.
• Strong SQL skills for data analysis, investigative queries, and working with complex datasets.
• Strong understanding of network and web protocols commonly associated with cyber threats and fraud, including HTTP, TLS, SMTP, and DNS.
• Practical understanding of cybersecurity investigations, threat analysis, anti-fraud activities, or incident response.
• Ability to combine software engineering and cybersecurity knowledge to develop practical defensive solutions.
• Bachelor's degree or equivalent qualification.

Soft Skills:

• Strong team orientation with a customer-first mindset and the ability to collaborate effectively across technical and non-technical teams.
• Leadership potential and the ability to take ownership of security initiatives and project activities.
• Analytical and investigative mindset with a strong interest in understanding complex cyber threats.
• Passion for continuous improvement, technical innovation, and ongoing learning.
• Strong professional integrity and commitment to maintaining a rigorous Code of Ethics.
• Proactive problem-solving approach with the ability to investigate unfamiliar threats and develop practical countermeasures.

Language Requirements:

• Japanese: Intermediate to business-level proficiency required, ideally JLPT N1-N2, for team collaboration and technical communication.
• English: Intermediate to business-level proficiency for communication within an international technology and cybersecurity environment.

Preferred Skills & Qualifications

• Programming experience with additional languages such as Java, C/C++, C#, Go, Ruby, Perl, Bash, or PowerShell.
• Practical experience with object-oriented programming (OOP).
• Hands-on experience in CSIRT, cybersecurity incident response, or B2C/B2B security operations.
• Knowledge of Japanese laws and regulations relating to cybercrime, cybersecurity, and unauthorised system access.
• Experience developing security automation, threat analysis, or investigative tools.
• Familiarity with OSINT methodologies, threat intelligence platforms, or dark web research.
• Experience investigating phishing, online fraud, account abuse, or other cybercrime activity.

About the Company
Our client is a global technology and e-commerce leader operating an extensive ecosystem of digital services used by millions of customers.

With large-scale digital platforms and continuously evolving technology, protecting users and services from sophisticated cyber threats is a critical business priority. Its dedicated Cyber Security Defense function combines security engineering, threat intelligence, incident response, automation, and anti-fraud expertise to address real-world cybercrime.

You will join a technically focused environment where cybersecurity professionals work with large datasets, modern security technologies, and international teams to strengthen the organisation's global cyber defence capabilities.
Why You'll Love Working Here

• Take on a high-impact cybersecurity role directly protecting millions of users and a large-scale digital ecosystem from real-world cybercrime.
• Work with Python, SQL, OSINT, threat intelligence, CSIRT, and security automation in a hands-on engineering environment.
• Join a specialised anti-fraud and Cyber Security Defense team focused on phishing, fraud, and emerging cyber threats.
• Work with large-scale datasets, modern threat intelligence capabilities, and automated security frameworks.
• Gain opportunities to lead high-visibility cybersecurity initiatives and collaborate with international security teams.
• Build specialist expertise spanning cybercrime investigation, incident response, software engineering, and threat intelligence.
• Work in a technology culture focused on engineering excellence, continuous learning, and innovation.
• Benefit from flex time, minimal overtime, and casual clothing.

Don't Miss Out - Apply Now!