Tech Lead / Cloud Site Reliability Engineer (SRE), Cloud Engineering Section (RMI Cloud Platform Dep)

Job Description:

About Organization

Cloud Platform Department is responsible for providing Rakuten Mobile's foundational virtual infrastructure. Within this division, the Cloud Technology Department specifically handles the design, build, and operation of virtualization platform software for containers and virtual machines.

This department comprises engineers with advanced cloud technology expertise, playing a pivotal role in Rakuten Mobile's globally unprecedented "fully virtualized cloud-native mobile network." The work involves creative and innovative contributions that continuously evolve the mobile network. The objective is to build a lean and highly efficient organization, systematize operations for continuous improvement, and enhance the technical capabilities of the organization.

The department consists of approximately 50 members. It is structured into five sections: three SRE sections responsible for the engineering and operations of specific technology domains (virtualization platform, container platform, storage platform), one section dedicated to developing a part of the container platform, and one section that spans across these four, focusing on developing and systematizing the verification environment and driving automation. The majority of members are engineers working at the forefront of telecom cloud technology.

Job Duties

Primary responsibilities include the design, build, and operation of the Telecom Cloud Platform. In-house operations are strongly promoted, entailing responsibility for designing, verifying, and deploying into commercial environments, as well as performing operational work. This also involves continuously improving the efficiency of day-to-day operations and planning for future needs.

As a technical leader, proactive driving of business improvements and contribution to the development of team members are expected. Main stakeholders include vendors providing cloud platforms as products, as well as the departments responsible for telecom applications (users of the cloud platform) and their respective vendors.

Mandatory Qualifications

• 5+ years of combined experience in designing, building, and/or operating telecom clouds (on-premises private clouds).
• Extensive experience with Kubernetes, including deploying, managing, and troubleshooting clusters in production.
• Certified Kubernetes Administrator (CKA) or equivalent certification.
• Strong Linux expertise, including experience with performance tuning, troubleshooting, and scripting.
• Solid networking fundamentals for cloud and telecom environments.
• Proven ability to create detailed technical documentation, including requirements, HLD (High-Level Design), and LLD (Low-Level Design) documents.
• Strong troubleshooting skills across multiple stacks: hardware (servers), OS (Linux), networks, Kubernetes, and cloud platform software.
• Proven experience in incident management and root cause analysis in production environments.
• Development expertise in designing and implementing operational efficiency and automation tools (e.g., Ansible, Python).
• Proven management and communication skills to lead operations as a technical leader, including progress and risk management.

Preferred Qualifications

• Experience with cloud-native technologies, including Istio, Helm, and Prometheus.
• Knowledge of standardization for the Telecom industry (e.g., 3GPP).
• Expertise in hybrid cloud environments, integrating on-premises private clouds with public cloud services.
• Familiarity with Continuous Integration/Continuous Deployment (CI/CD) pipelines and tools like Jenkins, GitLab.
• Understanding of observability practices, including experience with Grafana for visualization and Prometheus for monitoring metrics.
• Strong understanding of virtualization technologies like VMware or KVM.
• Relevant Linux certifications (e.g., RHCSA, RHCE) are highly preferred.

Languages:

English (Overall - 3 - Advanced)