Platform Engineer

About the Role

Mujin is hiring a Release Engineer for a growing team to focus on shaping and building scalable, reliable processes for software packaging, validation, and delivery rather than just building features.
Regular releases are critical to maturing MujinOS as a product, ensuring consistent quality and completeness across complex systems. Turning ongoing development into stable, releasable versions requires not only coordination, but also development of internal tooling, workflows, and automation systems.
In this role, you will make releases more predictable, efficient, and scalable by designing and developing release workflows, internal tools, and quality gates—while staying hands-on with release-stage QA and integration validation.
You will work closely with engineers responsible for our core software systems, QA, and documentation owners, helping ensure that what is built can be confidently released, clearly understood, and effectively used by both internal teams and end users.

Responsibilities

- Build software that engineers rely on: Develop and improve internal tools and services that support engineers across Mujin.

- Shape the developer experience: Work across CI/CD, build tooling, release workflows, documentation tooling, log collection, and internal support workflows.

- Work on a broad range of engineering problems: Contribute to both new tools and existing systems, with opportunities to work across Rust, Go, and Python.

- Build for modern development environments: Develop and improve tooling and services used in containerized environments, including Docker and Kubernetes.

Minimum Requirements

- 3+ years of professional software engineering experience

- Hands-on experience designing and building software services, command-line tools, developer tools, or internal engineering systems

- Professional programming experience with at least one general-purpose language such as Rust, Go, Python, C++, or a comparable language

- Experience contributing to software across multiple technical areas or layers of a system

- Understanding of software development workflows, including areas such as CI/CD, build systems, testing, deployment, or release processes

- Ability to collaborate with engineers and understand the needs of internal users

Preferred Requirements

- Experience working in a Platform Engineering, Developer Experience, Engineering Enablement, or similar team

- Experience building tools or services used by a large engineering organization

- Experience with Rust, Go, or Python

Interview Process

- Resume Screening

- Take-home coding test

- HR interview

- Technical interview

- Culture/Team fit interview

Attractives

- Impact engineering at scale: Build tools and services used by engineering teams across Mujin.

- Broaden your engineering experience: Work across a wide range of areas, from CI/CD and build tooling to release and support workflows.

- Build, not just operate: This is a software engineering role where you will develop tools and services, rather than focusing primarily on infrastructure operations.

Location
3-8-5 Tatsumi, Koto-Ku, Tokyo 135-0053, Japan
Work Hours
8:45 - 17:45 (with a 60-minute break)
Salary
Based on experience and skills
Salary revision twice a year
Additional bonuses are available based on performance
Holidays
Every Saturday and Sunday
Annual paid leaves
Maternity leave and Childcare leave
Flex Holiday (take public holidays on days of your choice)
Other holidays as defined by the company
Company Benefits
Explore Mujin Perks & Welfare Benefits
Flexible dress code policy
Commuting allowance
Japanese Social Security (Health Insurance, Pension, Labor Insurance)
Monthly team dinner support
Free buffet lunch every workday
Free vending machines (offering drinks and snacks)
High-end coffee machine
Exclusive Employee Gym Access
Japan Relocation Support
Visa sponsorship
Flight ticket support
Shipping expenses coverage up to a specified limit
Assistance for housing