Cloud Software Developer, Cloud Engineering Department (RMI Cloud Platform Dep)
Rakuten
·Jul 31, 2026
- Location
- Rakuten Crimson House, Japan
- Type
- Full-time
- Department
- Engineering
- Closing date
- Today
- Source
- Workday
Description
Job Description:
About Organization
Cloud Platform Department provides Rakuten Mobile's virtual infrastructure. Within this department, the Cloud Technology Department is specifically responsible for the design, build, and operation of virtualization infrastructure software for containers and virtual machines.
Working alongside engineers who possess advanced cloud technology crucial to Rakuten Mobile's globally unprecedented "fully virtualized cloud-native mobile network," this role offers the opportunity to engage in creative and innovative work that continuously evolves the mobile network.
The department comprises approximately 50 members. It is structured into five sections: three SRE sections responsible for the design, build, and operation 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 actively engaged in cutting-edge cloud technology.
Job Duties
This role involves the design and development of container-based virtualization infrastructure.
The main responsibilities include the integration of hardware (HW), operating systems (OS), virtualization infrastructure software, and third-party components operating on the virtualization infrastructure, all necessary for providing virtualization infrastructure for mobile communication systems.
The work will utilize Rakuten Symphony's Kubernetes-based virtualization infrastructure software. This includes design for various components, automation of infrastructure construction, and development tasks related to performance tuning. Additionally, the role involves considering and implementing necessary functionalities to ensure the stable and efficient delivery of Rakuten Mobile's services.
The working language for this position is English.
Mandatory Qualifications
Linux: Deep understanding of the internal structure of the Linux OS, including the kernel, system calls, network stack, and file systems.
Kubernetes: Experience in cluster building, operation, and troubleshooting. Specifically, the ability to understand the behavior of components like kubelet, etcd, and CNI, and perform performance tuning and debugging.
Container Technologies: Deep knowledge of container runtimes such as Docker and containerd. Understanding of container isolation, namespaces, cgroups, and other mechanisms.
Programming: Experience in developing automation tools, operators, and custom controllers using languages such as Go, Python, and Rust.
Scripting: Experience in automation using bash and shell scripts.
IaC (Infrastructure as Code): Experience in infrastructure management using tools like Terraform, Ansible, and Helm.
Networking: Foundational knowledge of networking, including TCP/IP, DNS, routing, and firewalls.
Preferred Qualifications
Linux Kernel: Experience in performance analysis and troubleshooting using tools like eBPF, perf, and ftrace.
Distributed Systems: Knowledge of designing and operating distributed systems.
Storage: Knowledge of distributed storage and file systems such as Ceph, NFS, and iSCSI.
Security: Knowledge of hardening security for Linux and Kubernetes.
OSS Contribution: Experience contributing to open-source projects.
Languages:
English (Overall - 3 - Advanced)