■ Job Title
Backend Engineer Leader
For someone living in Japan!
■ Company Overview
A tech-driven company focusing on transforming financial services through innovative solutions. They provide numerous services that help simplify financial management for both individuals and businesses.
■ Your Role and Responsibilities
Develop HR solution products using Ruby on Rails or Kotlin. (Most products are currently in Ruby on Rails; Kotlin migration is underway.)
Design and implement detailed specifications for new product features.
Refactor and enhance existing codebases and test coverage.
Ensure high product quality through thorough code reviews and testing.
Identify development issues, suggest improvements, and implement solutions.
Plan and design cross-product system architecture.
■ Experience and Qualifications
Bachelor’s degree in Computer Science, Engineering, or a related technical discipline.
5+ years of hands-on experience in designing, developing, and maintaining web applications.
Proven ability to mentor and support junior or peer engineers, fostering growth and technical development.
Active participation in team-wide quality initiatives such as code reviews and test implementation.
Strong skills in independently analyzing and refactoring systems using design patterns and addressing code anti-patterns.
Experience handling incident response: root cause analysis, rapid resolution, and long-term fixes.
Ability to adapt to diverse technology stacks and readiness to learn Ruby on Rails if not already proficient.
Japanese: Basic proficiency is a plus (reading and understanding technical documents).
English: Fluent in both written and spoken communication.
Technology Stack
Backend: Ruby, Ruby on Rails, GraphQL, gRPC, Sidekiq Pro, RSpec, Kotlin
Frontend: TypeScript, Next.js, Vue.js, Nuxt.js, Bootstrap-vue, Vue Apollo, Jest
Infrastructure: AWS (EKS, Aurora, ElastiCache, S3), Terraform
Tooling:
Source control: GitHub
Project tracking: JIRA
Monitoring: Datadog, Rollbar
CI/CD: CircleCI, ArgoCD, GitHub Actions
Communication: Zoom, Slack, Figma, Miro
■ Additional Preferred Qualifications
Familiarity with Ruby, Ruby on Rails, Kotlin, SpringBoot, and React.
Experience working in Agile environments, particularly Scrum-based teams.
Skilled in designing, writing, and executing tests using tools such as RSpec, Jest, JUnit, or Playwright.
Proficiency in middleware performance tuning, including database optimization.
Experience designing, building, and operating microservices and understanding scalable architecture.
Ability to make sound architectural decisions and choose appropriate technologies.
Experience developing AI solutions or utilizing AI tools to optimize the development lifecycle.
■ Good Reasons to Join
- Engage with advanced financial technologies.
- Lead impactful projects in a dynamic and innovative environment.
- Work within a collaborative, international team setting
■Work Style
Hybrid work, 2-3 days to the office.
■Work Location
Tokyo
■Salary
Negotiable