■ Job Title

Senior software engineer (Kotlin/Java)

Need 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 

Design, develop, and maintain high-performance backend systems using Kotlin or Java, ensuring scalability and reliability.
Collaborate with cross-functional teams to conceptualize, architect, and implement new features that enhance SaaS offerings.
Evaluate existing features and develop strategies for short-, medium-, and long-term migration or re-architecting to support platform growth and scalability.
Identify and address cross-team technical challenges, making key decisions that shape the engineering direction.
Diagnose and resolve performance bottlenecks across multiple products to ensure service efficiency and responsiveness.
Design and implement robust, maintainable APIs for both internal and external integrations.
Partner with product managers, designers, and engineers to translate requirements into high-quality solutions.
Foster a culture of learning and growth through proactive knowledge sharing across teams and the organization.
Create and maintain comprehensive technical documentation for systems, APIs, and processes.
Collaborate with support teams to troubleshoot and resolve technical issues efficiently.

 

■ Experience and Qualifications

 

Bachelor’s degree in Computer Science, Engineering, or a related technical field.
5+ years of hands-on experience in designing, developing, and operating web applications using Kotlin or Java with production-proven tools and frameworks.
Expertise in service-oriented or microservices architecture with a strong understanding of scalable, modular designs.
Proven experience in architectural design and technology selection to build optimal solutions.
Ability to independently analyze, design, and refactor code using design patterns while identifying and addressing anti-patterns.
Proficiency in performance tuning of middleware and database optimization.
Flexibility to work with diverse technology stacks, with a willingness to learn technologies such as Ruby on Rails, frontend frameworks, and others to enhance system performance.
Active participation in team-based quality improvements through code reviews and test code implementation.
Experience with test design and implementation using tools such as JUnit, Kotest, RSpec, Jest, or similar frameworks.
Demonstrated ability to mentor and guide team members, supporting their technical and professional development.
Hands-on experience managing incident responses, including root cause analysis, resolution, and implementing long-term fixes.

 

English: Fluent in both written and spoken communication.
Japanese: Not required (interest in learning is considered a plus).

 

Technology Stack
Backend: Kotlin, Java, Ruby, Ruby on Rails, GraphQL, gRPC, Sidekiq Pro, RSpec
Frontend: TypeScript, Next.js, Vue.js, Nuxt.js, Jest

Infrastructure: Amazon EKS, Aurora, ElastiCache, S3
Infrastructure as Code: Terraform
Repositories: GitHub
Project Management: JIRA
Monitoring: Datadog, Rollbar
CI/CD: CircleCI, ArgoCD, GitHub Actions
Communication Tools: Zoom, Slack, Figma, Miro

 

■ Additional Preferred Qualifications

 

Familiarity with Ruby, Ruby on Rails, React, or Vue.js.
Experience with containerization and orchestration tools like Docker and Kubernetes.
Hands-on experience with event-driven architectures or similar patterns to optimize system performance.
Previous experience working within Scrum or other Agile methodologies, contributing to effective and collaborative project delivery.
Prior experience in a SaaS environment is a plus.

 

■ 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