SOC Analyst - Security Operations Center Group, Cyber Defense Operations Section (RMI Security Eng. & Ops Dep)

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 mission is to evolve from a reactive monitoring unit into a proactive, intelligence-led, and automated defense organization.

We are looking for a highly technical and innovative SOC Analyst (L2) to act as a key architect of our future-ready SOC, leveraging LLMs and AI-powered tools to neutralize advanced adversaries. Job Duties AI-Driven Threat Defense: Utilize LLMs and AI-augmented security platforms to accelerate threat hunting, incident triage, and forensic analysis.

Develop workflows to identify and respond to autonomous AI-based attacks. SOC Transformation: Actively contribute to the SOC’s capability roadmap. Recommend and implement structural improvements to toolsets and processes to handle the evolving threat landscape. Container & K8s Security: Perform deep-dive analysis into containerized environments and Kubernetes clusters.

Implement security controls against container-specific exploits and automated lateral movement. Capacity Development: Participate in the continuous training and upskilling of the SOC team. Translate technical findings into new playbooks and SOPs to elevate the team's response maturity. Advanced Incident Response: Lead the investigation of complex incidents.

Apply "Defense in Depth" principles to identify environmental gaps and propose architectural hardening. Security Engineering: Collaborate with the L3 Manager to tune detection logic and integrate AI-based feedback loops into our SIEM/SOAR infrastructure. Offensive Security Research: Apply an "Off. Sec" mindset to simulate and test defenses against AI-powered attack tools, ensuring faster and more precise responses.

Minimum Qualifications

Bachelor’s degree in Computer Science, Cyber Security, or equivalent. 5–8 years of experience in a SOC, incident response, or security engineering role. Strong understanding of SIEM/SOAR ecosystems and optimization for AI-driven detection. Relevant certifications (e.g., GCIH, GCSA, CKAD, CKS, or AI-Security specific certifications).

Preferred Qualifications

Experience in the Telecommunications sector (e.g., 5G security, NFV, signaling protocols). Experience in developing custom AI/ML models or fine-tuning LLMs for security use cases. Demonstrable experience in "Red Teaming" or participating in high-level CTF competitions. Experience with Infrastructure as Code (IaC) and Dev.

Sec. Ops pipelines. Work Environment Reporting: Reports to the Manager of the Security Operations Center Group. Collaboration: Manages/mentors the 24/7 SOC team and collaborates cross-departmentally with other security functions and Business Units. Tech Stack: Containerization (Docker/Kubernetes), Telco environments (5G Core, Signaling Protocols), SOAR platforms, Python/Go/Bash, Cloud Security (AWS/Azure/GCP), and LLM-based security tools.

Languages: English (Overall - 3

• Advanced)