Backend Engineering · Contract
Kotlin Backend Engineer
Urgent
| Category | Backend Engineering |
|---|---|
| Location | Tokyo（Hybrid） |
| Employment | Contract |
| Salary | Negotiable |
| Posted | Aug 30, 2026 |
Overview
Design, build and test Kotlin/JVM backend services, microservices and APIs for a large-scale digital platform in Japan.
Responsibilities
- Design, implement and test backend services and APIs using Kotlin/JVM
- Integrate existing services, external APIs and data stores while making dependencies explicit
- Contribute code reviews and automated tests; improve performance, reliability and security
- Prepare technical inputs and options for architecture reviews
- Analyse and fix QA defects and support release readiness
- Collaborate in English across distributed teams and support phased knowledge transfer and operational handover
Requirements
- 3+ years of hands-on server-side development with Kotlin or Java
- Solid understanding of the JVM, microservices, REST APIs and database design
- Team development experience using unit/integration testing, Git and CI/CD
- Experience building for performance, incident handling, observability or production operations
- Able to read technical documentation and collaborate professionally in English
- Cloud, containers, messaging platforms or high-traffic systems experience is advantageous
Skills
KotlinJava / JVMMicroservicesREST APIAutomated TestingCI/CD