Senior Full Stack Software Engineer

Publication date 2026/02/6

Work Location , Expected Annual Income :

Tokyo,8.0M ～ 10.0M

About the Company :

Insurance company

Responsibilities :

Job Description
Develop fully tested frontend and backend applications using TypeScript.
Make architectural decisions and design scalable systems.
Continuously improve existing applications and identify areas for enhancement.
Review code for efficiency, readability, maintainability, and adherence to best practices.
Share knowledge and promote best practices within the engineering community.
Mentor and support junior and mid-level engineers.

Benefits :

Competitive company package
Full insurance coverage
Transportation

Required Experience / Abilities / Skills :

Qualifications
Required

7+ years of experience developing web applications using JavaScript/TypeScript.
Experience with React.js and/or Next.js for frontend development.
Ability to implement clean, responsive UIs using HTML/CSS.
Backend development experience with Node.js and frameworks like Express or Fastify.
Strong understanding of RESTful API design and Swagger/OpenAPI specifications.
Proficiency in relational databases (e.g., MySQL), schema design, and query optimization.
Willingness to learn new technologies such as Next.js and Serverless Framework.
Knowledge of software development best practices and scalable architecture design.
Experience with Agile/Scrum methodologies and AWS.
Ability to mentor other engineers and collaborate effectively using Git.
Business-level English (TOEIC 785+) and Japanese (JLPT N2+).
Degree in Computer Science or equivalent practical experience.
Preferred

Knowledge of Java/SpringBoot.
Understanding of NoSQL databases like DocumentDB and Redis.
Experience with OpenShift and/or Kubernetes.
Familiarity with serverless architecture and microservices.
Experience with CI/CD tools such as Jenkins and SonarQube.

Contact Information :

Jim Joseph
j-joseph@jac-international.jp

JOB ID : IJB2009438