English Speaking Senior Software Engineer

About the Role

As a Senior Software Engineer, you will contribute across the stack, taking features from design through production. You will own technically challenging projects, improve system quality, and help establish engineering practices that support long-term product growth. We value engineers who care about technical quality, end-user experience, and long-term stability—not simply shipping tickets quickly.

Key Responsibilities

• Design and deliver end-to-end features across frontend, backend, and software architecture.
• Own technically challenging projects, including refactoring, complex data modeling, and new platform integrations.
• Improve system reliability, performance, scalability, testability, and maintainability.
• Mentor other engineers and promote high standards in code quality and architecture.
• Participate in support rotations to investigate bugs and production incidents.
• Collaborate effectively with engineering, product, design, business operations, and other stakeholders.

Technology Stack

Our stack includes (but is not limited to):
• TypeScript across the stack
• Node.js
• Backend: NestJS, Prisma, PostgreSQL
• Frontend: React, Next.js
• Mobile: React Native (Expo)
• Cloud: AWS (EKS, S3, Lambda)
• Redis

Required Qualifications

• 7+ years of professional software engineering experience.
• Significant hands-on experience with TypeScript.
• At least 2 years of hands-on experience with React or a similar modern frontend framework.
• Strong understanding of backend frameworks, database modeling (SQL / Prisma), and asynchronous application architecture.
• Ability to collaborate across functions, including product, design, operations, and other stakeholders.
• A track record of delivering production systems with a focus on scalability, reliability, testability, and maintainability.
• Familiarity with modern development workflows, including Git, pull request reviews, CI/CD, and automated testing.
• Currently based in Japan or willing to relocate to Japan. Relocation support is available.

Nice to Have

• Experience with our technology stack, particularly NestJS, Prisma, PostgreSQL, and AWS.
• Experience developing and operating containerized applications (e.g., Docker).
• Cloud infrastructure experience, such as AWS or GCP.
• Familiarity with AI-assisted development tools and workflows, such as Claude Code or Cursor.
• Experience building B2B or enterprise SaaS products.
• Conversational Japanese ability.