Security Detection & Automation Engineer - Product Security Section, Cyber Security Defense Department (CSDD)

The Cyber Security Defense Department (CSDD) is responsible for safeguarding all Rakuten companies and users from cyber threats, ensuring the security and integrity of Rakuten Group's global internet services.

We oversee all aspects of both Secure Development and Security Operations for services developed within the group, with dedicated security teams and operation centers strategically located in key regions worldwide.

To deliver comprehensive cybersecurity by embedding robust security into the design, development, and delivery of Rakuten's products and protecting our production systems through high-fidelity detection, automated response, and scalable security engineering.

We are looking for a Security Detection & Automation Engineer to join our team. You will be responsible for building the "eyes and ears" of our security ecosystem. You will develop automated detection logic, engineer security-as-code solutions, and build response playbooks that protect our private cloud environment. Your goal is to reduce the time-to-detect and time-to-remediate through automation, ensuring our global services remain resilient against evolving threats.

Develop, tune, and maintain high-fidelity detection rules (SIEM/EDR/Cloud-Native tools) to identify malicious activity across our global hybrid cloud infrastructure

Design and implement automated workflows (SOAR) to respond to common threats, reducing manual toil for the security operations team

Partner with SRE and DevOps teams to integrate automated security guardrails into CI/CD pipelines

Proactively analyze logs, traffic patterns, and system telemetry to identify sophisticated threats that bypass traditional signature-based defenses

Build automated systems to verify the security posture of hybrid cloud configurations, ensuring continuous compliance and drift detection

Build custom internal tools or scripts (Python/Go) to bridge gaps in our security stack and improve visibility across our cloud ecosystem