Backend Developer

Applications: candidates may apply from outside Japan. Visa sponsorship: available. Japanese: Not required. English: Business level. Japan Dev tags: Engineering, Backend, Go, AWS, PostgreSQL, gRPC, Terraform.

About

We're looking for a backend engineer to design and build systems that power payment infrastructure. You'll own features end-to-end, from database schema design through deployment, and work alongside a small, tight-knit team of experienced engineers who ship fast and iterate constantly!

Responsibilities

• Design, implement, and maintain high-performance backend services in Go.
• Architect scalable data models and database schemas for new product features.
• Build and operate workflow orchestration systems to handle complex payment sequences.
• Identify and address technical debt while balancing rapid delivery timelines.
• Participate in peer system design reviews and thorough code reviews.
• Monitor, debug, and continuously improve overall system reliability.

Requirements

• Experience: At least 1 year of professional backend software development experience.
• Technical Proficiency: Strong proficiency in Golang and relational database design (PostgreSQL preferred).
• Orchestration: Experience with workflow orchestration systems such as Temporal or AWS Step Functions.
• System Design: Solid understanding of distributed systems patterns and architectural trade-offs.
• Delivery: Proven track record of delivering stable features in production environments.
• Documentation: Experience writing technical design docs, API specs, or SDK documentation.

Preferred Qualifications

• 2–5 years of professional software development experience.
• Experience shipping a product from zero to production (strongly preferred).
• Background in Fintech or Payments industries.
• Familiarity with Infrastructure-as-Code (Terraform) and gRPC/Protocol Buffers.
• Experience working in early-stage, fast-paced companies.
• Familiarity with fullstack, mobile, or modern frontend frameworks.