Senior Software Engineer (QA Platform Development)

Position Overview

We are looking for talented software engineers to join us for developing a platform for quality assurance and test automation. The ideal candidate has a strong background in software development, excellent coding skills, and a keen interest in software quality and test automation. While prior experience in test automation is preferred, we also welcome experienced developers eager to grow their expertise in testing.

This is a developer-heavy role with a testing focus — strong coding ability is an absolute requirement. You will design and build test tools, frameworks, and infrastructure to enable continuous testing at scale, collaborating closely with engineering teams to ensure high product quality through robust automation and well-architected test systems.

Job Duties & Responsibilities

Build and maintain robust testing platforms and automation frameworks for web and mobile applications (Android & iOS).

Automate end-to-end test scenarios for critical user flows and system validation.

Ensure scalability and reliability through load, performance, and cross-platform testing.

Perform manual testing for complex scenarios where automation is not feasible.

Maintain clear and comprehensive test documentation.

Integrate automated tests into CI/CD pipelines and collaborate with the team.

Expected Knowledge, Skills, and Abilities

Minimum 5 years of professional experience in B2B software development.

Strong coding skills in TypeScript and Python.

Strong debugging, analytical, and problem-solving skills.

Passionate about test automation with a strong ability to apply creative thinking to solve testing challenges.

Professional English communication skills.

Additional Desirable Knowledge, Skills, and Abilities

Experience with automation tools (e.g., Selenium, Appium, Playwright, and Espresso).

Experience in the implementation of automated end-to-end (E2E) test frameworks.

Knowledge of API testing (Postman, RestAssured, gRPC).

Experience with performance/load testing (e.g., JMeter, Locust, LoadRunner).

Exposure to modern frontend stacks such as React.

Experience in applying AI/ML techniques in testing.

Familiarity with web communication protocols (gRPC, OAuth2/OIDC).

Infrastructure experience with Kubernetes, Docker, CI/CD, and cloud platforms.

Work Hours

Flexible working hours

Core collaboration availability: Tue - Fri: 9am - midday (JST)

Location

Hybrid / In-Office (Tokyo)

We have a fantastic office in Nihonbashi, Tokyo.

In general, you can work remotely from home.

The QA team will have weekly in-person meetings at the office to collaborate and socialize.

Working from the Tokyo office may be required, such as during the first three months for onboarding.

Salary Range

JPY 8,000,000 – JPY 12,000,000（※1）:

Estimated annual salary: Base Salary (12 months) + Bonus (Base salary x 1 month x twice a year = 2 months)

Monthly salary system: Base salary is determined based on your skill set, experience, and abilities, etc.

An allowance for additional overtime（※2）is included in the base salary.

・However, work exceeding additional overtime agreed to between the employer and employee will be compensated separately.

Base monthly salary（※1）: JPY 570,000 – JPY 860,000

The base monthly salary breakdown as follows:

・Base salary: JPY 434,250 – JPY 655,200

・Allowance for additional overtime（※2）: JPY 135,750 to JPY 204,800

※Notes:

Depending on your skill set and experience, the amount set may be outside the above range.

Calculated based on 160 hours of scheduled working hours per month and 40 hours of additional overtime.

Benefits

Remote work allowance (5,000/month)

Employee stock ownership plan (company matches purchase of up to 10% of paycheck)

Skill development support/Language Learning Support (120,000 yen a year)

New tech gear (Mac/PC)

Commuter allowance

Comprehensive health and social insurance

Parental Leave

Visa sponsorship and relocation support will be provided for those who do not reside in Japan.

Vacations

20 days of paid leave

5 days of Proactive Personal Leave

5 days of Family Care / Personal Sick Leave

Two days off per week (Saturday and Sunday), Public holidays in Japan