English Speaking Senior Software Engineer — Platform

The CTO Office is driving the development of an AI-based ontology architecture for enterprise customers, alongside shared foundations and platforms that help the organization scale. It is built around an ontology: a next-generation, AI-powered semantic layer designed to understand context across business data, workflows, and operations.

In this role, you will help advance this architecture as a senior full-stack engineer, with particular emphasis on backend systems. You will work across a range of company systems, identify opportunities to improve the engineering environment, and take ownership of improvements from idea through implementation.

Key Responsibilities

• Contribute to the design and development of Atlas and its supporting platform architecture.
• Build and improve core platform infrastructure and developer tooling.
• Develop and maintain CI/CD systems and related engineering workflows.
• Analyze infrastructure and application performance and implement improvements.
• Address cross-team and socio-technical challenges by setting a strong engineering example and building tools that solve recurring problems.
• Take initiative to identify high-impact work and deliver improvements at an organization-wide level.
• Contribute to a broad range of software systems as business and technical needs evolve.

Technology Stack

The stack includes (but is not limited to):
• TypeScript across the stack
• Node.js
• React
• MongoDB
• AWS: ECS, CloudFront, S3, SQS, and Lambda
• Vercel
• Redis
• Datadog for observability and monitoring

Required Qualifications

• Senior-level understanding of cloud infrastructure, such as AWS, and distributed systems.
• Production experience with observability or monitoring platforms; Datadog experience is particularly relevant.
• Strong software development skills comparable to those of a senior full-stack engineer.
• Ability to communicate in English in a professional setting. Full fluency is not required, but you should be comfortable using English as part of the role.
• Strong commitment to code quality, documentation, and automated testing.
• A proactive mindset: able to identify useful work independently and take action.
• Willingness to work across different areas and contribute to software systems throughout the company.
• Conversational Japanese, or a genuine willingness to learn Japanese. Support will be provided.
• Currently based in Japan or willing to relocate to Japan. Relocation support is available; please indicate your current location in your application.

Nice to Have

• Experience programming in a statically typed language, ideally TypeScript.
• Experience with CDK-TF or strong practical experience with Terraform.