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

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

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

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