Senior Network Security Engineer

To support Rakuten Mobile’s rapid growth, we are continuously expanding our Linux/Kubernetes-based platforms and enhancing our authentication and secrets management capabilities.

The Network Security Engineering Section designs and operates secure network services using an advanced technology stack including Linux, RHEL, Kubernetes, IPA/FreeIPA, and Vault.

Linux Infrastructure: Design, build, operate, and troubleshoot Red Hat Enterprise Linux and diverse Linux environments.

Kubernetes Security: Securely operate, configure, and optimize Kubernetes clusters and related components to meet growing operational demands.

Identity & Access Management: Manage authentication, user lifecycle, authorization, and policies using IPA/FreeIPA.

Secrets & Certificate Management: Design and operate secrets management, PKI/certificate management, and access control using HashiCorp Vault or equivalent tools.

Security Hardening: Perform security hardening, patch management, and audit support for Linux/Kubernetes environments to ensure high security standards.

Automation: Drive configuration management, automation, and standardization using tools such as Ansible to improve operational efficiency.

Incident Management: Handle incidents, conduct root-cause analysis (RCA), and implement preventive measures for mission-critical services.

Cross-functional Collaboration: Work closely with network, cloud, security, and operations teams, utilizing English for technical communication and project coordination in a global environment.

Department: Network Security Engineering Section, Security Engineering Department.

Collaboration: Work alongside global teams with diverse backgrounds in Linux, networking, security, cloud, and Kubernetes.

Stack: RHEL, Kubernetes, IPA/FreeIPA, Vault, Ansible, Git, CI/CD, and various monitoring/logging tools across on-premises and cloud environments.

English (Overall - 3 - Advanced)