Job Description: About Organization Cyber Defense Operations Section operates a 24/7 Security Operations Center (SOC) protecting Rakuten Group's critical infrastructure. We are currently in a critical transformation phase to address the era of autonomous, AI-driven cyber threats. Our goal is to evolve from a reactive monitoring unit into a proactive, intelligence-led, and autonomous defense organization. We are seeking a visionary and hands-on SOC Lead to architect our future-ready security operations, leveraging AI and automation to neutralize machine-speed attacks while mentoring high-performing security talent. Job Duties Strategic Transformation: Lead the evolution of the SOC from a reactive monitoring unit to an autonomous, AI-augmented defense organization. AI & Automation Engineering: Architect and implement AI-driven detection and response workflows. Drive the integration of SOAR (Security Orchestration, Automation, and Response) to counter autonomous AI attacks. Operational Leadership: Manage the 24/7 SOC team, ensuring high-availability monitoring, rapid incident response, and continuous service improvement. Technical Oversight: Provide L3-level escalation support for complex incidents. Oversee security monitoring of Telco-specific network architectures, containerized environments, and Kubernetes (K8s) clusters. Governance & Documentation: Establish rigorous SOC governance, including the creation and maintenance of playbooks and SOPs that meet international audit and compliance standards. DFIR & Root Cause Analysis: Assist in high-stakes Digital Forensics and Incident Response (DFIR) efforts, conducting deep-dive analysis to harden the environment against future threats. Stakeholder Collaboration: Partner with cross-functional security teams and Business Units to ensure security is integrated throughout the infrastructure lifecycle. Innovation & Research: Stay at the bleeding edge of offensive and defensive AI research to proactively adapt security posture against evolving adversary tactics. Minimum Qualifications Leadership: Proven experience leading technical teams in a 24/7 environment; demonstrated ability to mentor and grow security talent. AI/ML in Security: Deep understanding of leveraging AI for threat hunting, anomaly detection, and automated response. Telco & Infrastructure: Strong experience in a Telco environment, including knowledge of SS7/Diameter/GTP protocols, 5G core security, and virtualization. Cloud-Native Security: Expert-level knowledge of containerization (Docker) and Kubernetes (K8s) security. Automation: Advanced scripting skills (Python, Go, or Bash) and extensive experience with SOAR platforms. DFIR: Expert capability in conducting digital forensics and managing incident response lifecycles. Experience: 10+ years in Cyber Security, with at least 6 years in a leadership role within a SOC. Education: Bachelor's or Master's degree in Computer Science, Cyber Security, or a related field. Certifications: Relevant industry certifications (e.g., CISSP, CISM, GCIH, GCFA, or equivalent). Preferred Qualifications Experience with LLM-based security tools or "AI-vs-AI" defense strategies. Experience in high-traffic, low-latency environments typical of modern Telecommunications. Active participation in the security community (e.g., public speaking, research papers, or open-source security tool development). Experience with cloud security (AWS/Azure/GCP) in a hybrid-Telco environment. Work Environment Reporting: Reports to the Head of Cyber Defense Operations Section. Collaboration: Manages the 24/7 SOC team and collaborates cross-departmentally with other security functions and Business Units. Tech Stack: Containerization (Docker/K8s), Telco environment (5G Core, Signaling Protocols), SOAR platforms, Python/Go/Bash, Cloud Security (AWS/Azure/GCP), and LLM-based security tools. Languages: English (Overall - 3 - Advanced) Looking for members to join our mobile phone business “They cannot succeed if they step into the field at this late date” Some people say Rakuten is reckless in trying to enter the mobile communications business. However, innovation is realized if we succeed when something seems impossible. At Rakuten, we think the world changes when we achieve such changes. Because our history has always been a series of innovations since our establishment. Launching a communication carrier is an opportunity that we have once in our lives. Crack open the current communication industry. Blow new wind into life. Why not create innovation with us? Why not do something big? Job Opening: Regular Employee Company Name Rakuten Mobile, Inc. Qualifications [Required] TOEIC score of 600 or equivalent English proficiency/skills. Rakuten Group Englishnization Rakuten Mobile, Inc. aims for all employees to achieve a TOEIC score of 800 or higher, in line with Rakuten Group, Inc.'s Englishnization policy. As a first step, a TOEIC score of 600 (or equivalent English proficiency) is required for mid-career hires. Job Responsibilities [Upon initial hiring] Varies depending on the position. The scope of work changes may include assignments to other duties determined by the company based on directives, etc. (If a transfer is ordered in accordance with the secondment regulations, the duties will be those of the seconded company.) Contract Period No fixed term Probationary Period Yes (3 months) The probationary period may be extended at the company's discretion. Employment conditions will not change during the probationary period. Work Location [Upon initial hiring] Headquarters (Rakuten Crimson House, 1-14-1 Tamagawa, Setagaya-ku, Tokyo), and other business sites. The scope of work location changes may include reassignments or transfers to locations nationwide and overseas. If remote work is partially permitted, the work location will be the remote work location approved by the company. The work location at the time of hiring will be communicated in the job description for each position and the offer letter. As a measure against passive smoking, smoking is prohibited on the premises of Rakuten Crimson House (however, this may vary depending on the business site). Working Hours Standard working hours: 9:00 AM - 5:30 PM On days when Rakuten Group morning meetings are held, the prescribed working hours will be 8:00 AM - 4:30 PM. Prescribed working hours are 7.5 hours, with a 1-hour break. A flextime system is partially applied. Core time: 11:00 AM - 3:00 PM (8:00 AM - 12:00 PM on morning meeting days) Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Overtime work or work on holidays may be instructed. Holidays/Leave/Absence Complete two-day weekend system (Saturday and Sunday) and national holidays Summer vacation, New Year's holiday, annual paid leave, menstrual leave, special leave (condolence, volunteer, etc.) Maternity leave, childcare leave, family care leave Some positions may differ from the above; details will be specified in the offer letter. Salary Monthly salary: JPY300,000 ~ (Breakdown: Base salary JPY 227,848 + fixed overtime pay for 40 hours JPY 72,152) The above is the minimum salary offered for mid-career hires. Overtime work exceeding 40 hours per month will be paid separately as overtime allowance. Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Commuting allowance will be provided (conditions and maximum amount apply). Salary Increase Yes Reviewed in January and July based on company performance and individual evaluation. Bonus Yes Paid in June and December based on company performance and individual evaluation. Stock Option Plan Yes Retirement Allowance Yes Insurance Employees' Pension Insurance, Health Insurance, Workers' Accident Compensation Insurance, Employment Insurance, etc. Benefits Cafeteria (breakfast, lunch, dinner generally free) Employee Stock Ownership Plan English learning support, etc. Job Opening: Fixed-term Employee Company Name Rakuten Mobile, Inc. Qualifications Varies depending on the recruiting position. Job Responsibilities [Upon initial hiring] Varies depending on the recruiting position. The scope of work changes may include assignments to other duties determined by the company based on directives, etc. (If a transfer is ordered in accordance with the secondment regulations, the duties will be those of the seconded company.) Contract Period Fixed term Maximum contract renewal period: Yes (The total contract period is 5 years, starting from the initial employment contract date.) Probationary Period None Work Location [Upon initial hiring] Headquarters (Rakuten Crimson House, 1-14-1 Tamagawa, Setagaya-ku, Tokyo), and other business sites. The scope of work location changes may include reassignments or transfers to locations nationwide and overseas. If remote work is partially permitted, the work location will be the remote work location approved by the company. The work location at the time of hiring will be communicated in the job description for each position and the offer letter. As a measure against passive smoking, smoking is prohibited on the premises of Rakuten Crimson House (however, this may vary depending on the business site). Working Hours Standard working hours: 9:00 AM - 5:30 PM On days when Rakuten Group morning meetings are held, the prescribed working hours will be 8:00 AM - 4:30 PM. Prescribed working hours are 7.5 hours, with a 1-hour break. A flextime system is partially applied. Core time: 11:00 AM - 3:00 PM (8:00 AM - 12:00 PM on morning meeting days) Some positions may differ from the above; details will be specified in the offer letter (e.g., application of discretionary labor system). Overtime work or work on holidays may be instructed. Holidays/Leave/Absence Complete two-day weekend system (Saturday and Sunday) and national holidays Summer vacation, New Year's holiday, annual paid leave, menstrual leave, special leave (condolence, volunteer, etc.) Maternity leave, childcare leave, family care leave Some positions may differ from the above; details will be specified in the offer letter. Salary Determined individually based on experience, etc. Commuting allowance will be provided (conditions and maximum amount apply). Salary Increase Yes Upon contract renewal, a salary revision may be proposed based on the most recent evaluation. Bonus May be paid taking into account company performance, general economic conditions, and work performance/abilities. Stock Option Plan None Retirement Allowance None Insurance Employees' Pension Insurance, Health Insurance, Workers' Accident Compensation Insurance, Employment Insurance, etc. Benefits Cafeteria (breakfast, lunch, dinner generally free) Employee Stock Ownership Plan English learning support, etc.

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