Software Development Engineer in Test (SDET)

KOMOJU Musashino-Shi, Tokyo
  • 💴 No salary range given
  • 🏡 Fully remote (within Japan)
  • 🧪 2+ years experience required
  • 💬 No Japanese required
  • 🌏 Apply from abroad
  • 🧳 Relocate to Japan
DO YOU NEED MORE INFO?
ASK A QUESTION

About KOMOJU

KOMOJU Musashino-Shi, Tokyo

The leading cross-border payment gateway for Japan. We power payments for companies like video game distribution platform Steam and the popular mobile app TikTok.

Key benefits

  • Developer-centric, inclusive culture
  • International at our core
  • Generous holiday policy

About the position

We are looking for passionate SDETs to join KOMOJU’s growing QA team. In this hybrid role, you will contribute to both automated and manual testing efforts to ensure the reliability, functionality, and performance of our payment systems.

As an SDET, you will help shape and drive QA processes from the ground up. You will be working cross-functionally with engineers, product managers, and business stakeholders to define and measure quality at every level of our stack. This is a great opportunity for someone who thrives in a collaborative environment and is eager to grow their technical and testing skills.

Responsibilities

  • Design, develop, and maintain automated test frameworks and tools to improve test coverage and reliability.
  • Execute and manage manual, exploratory, and regression testing for new features and releases.
  • Analyze system specifications and technical requirements to provide feedback and ensure testability.
  • Identify, document, and track bugs through resolution, contributing to improved product quality.
  • Support the team by building and maintaining CI/CD test pipelines and integrating automated tests into release workflows.
  • Collaborate with developers to ensure proper testing is done throughout the development lifecycle.
  • Participate in code reviews and test plan reviews.
  • Help establish quality processes and best practices across the engineering team.
  • Investigate and recommend tools or practices that help scale QA and improve team productivity.

Requirements

  • 2–5 years of experience in software testing, automation, or software development.
  • Proficient in at least one programming language (e.g., TypeScript, JavaScript, Python, or Ruby).
  • Hands-on experience with automated testing tools such as Playwright, Selenium, Capybara, or RSpec.
  • Strong understanding of testing methodologies including unit, integration, and E2E testing.
  • Experience writing and executing test plans and test cases, both automated and manual.
  • Familiarity with CI/CD pipelines and test automation integration.
  • Ability to work independently in ambiguous environments with a strong bias toward action.
  • Excellent communication and debugging skills.

Nice to haves

While not specifically required, tell us if you have any of the following.

  • Experience testing multilingual or mobile applications.
  • Familiarity with AWS, monitoring tools like Datadog, or performance testing.
  • Exposure to backend systems, APIs, or infrastructure.
  • Experience working with agile teams or in fast-paced startup environments.
  • Open-source contributions.
DO YOU NEED MORE INFO?
ASK A QUESTION

Meet KOMOJU's Developers

Nicole joined KOMOJU in 2020, and worked her way up to be technical lead of the merchant management team. She shares her journey, how KOMOJU supported her career growth and how the company is adapting to its growing needs.

Read their story...

Nigel was fresh out of college when he joined KOMOJU as a developer. He's now risen to tech lead, where he's helped build out their payment platform while maintaining a healthy work-life balance.

Read their story...

Muhammad Denaw, Senior Site Reliability Engineer at Komoju, talks about his work and shares how Komoju's trust and support propelled him to a promotion.

Read their story...

Head of Customer Engineering Makoto Mizukami describes the unconventional candidates his unique team is looking for.

Read their story...

Related jobs

More jobs like this

I'll send you a digest of new English-friendly software developer jobs in Japan. Your email stays private, I don’t share or sell it.