Senior Software Engineer

Are you an experienced engineer who thrives on solving complex system architecture challenges?

Fast-growing international tech company in Tokyo is looking for a Senior Software Engineer to lead the transition from a core monolith to a scalable Service-Oriented Architecture.

In this role, you will act as a technical lead shaping architectural strategy, driving domain boundaries, and selecting the modern tech stack to support rapid Asian market expansion.

Key Responsibilities

• Tech Stack Selection: Evaluate and choose modern, statically-typed languages for future services, prioritizing type safety, concurrency, and developer experience.
• Domain & Technical Leadership: Partner with product managers to refine technical specifications, define domain boundaries, mentor engineers, and set engineering standards.
• High-Reliability Engineering: Design scalable database schemas and distributed workflows that ensure transaction integrity, payment consistency, and high availability.
• DevOps & Observability Culture: Drive a "you build it, you run it" culture by implementing zero-downtime deployment strategies, CI/CD pipelines, and robust monitoring.

Requirements

• Statically-Typed Languages: Demonstrated experience with languages such as Go, Kotlin, Scala, Rust, or C#, including async/concurrency paradigms.
• SOA & Monolith Refactoring: Proven background designing SOA/microservices while maintaining and refactoring monolithic codebases.
• Database Scalability: Hands-on experience with scalable storage and database solutions (e.g., AWS Aurora, Cassandra).
• CI/CD & Observability: Practical experience with CI/CD tools (GitHub Actions, CircleCI) and monitoring/logging stacks (Datadog, Grafana, Prometheus).
• Communication & Ownership: Fluent written and verbal communication skills in English with an entrepreneurial, problem-solving mindset.

Nice-to-Have

• Experience with Ruby and Ruby on Rails.
• Japanese language proficiency.

Benefits

• Commuting allowance: paid in accordance with company regulations
• Full social insurance (employment, workers' compensation, health, and pension)
• Saturdays, Sundays and national holidays
• Annual paid vacation: 10 days at the time of employment
• Year-end and New Year vacations: 6 days from December 29 to January 3