Software Quality Assurance Engineer

Mid to Senior QA Engineer – AI SaaS

📍 Tokyo | Office-first Hybrid (4 days office / 1 day remote)

Our client is searching for a talented and ownership-driven QA Engineer to join a fast-growing AI SaaS company building cutting-edge creative technology for global enterprise brands. This is a product-focused quality engineering role where you'll own quality across the full feature lifecycle — from requirement review and test planning all the way through to production monitoring and continuous improvement.

SUMMARY:

• Product-focused QA Engineering role responsible for ensuring quality and reliability across frontend, backend, APIs, AI-powered workflows, and production releases at a fast-moving AI SaaS company
• High-ownership position working closely with Product, Design, and Engineering to translate requirements into test strategies, identify risks early, and prevent bugs through better processes, automation, and tooling — not just find them
• Tokyo office-first hybrid role (4 days in office); fluent English required, Japanese is a plus; open to mid and senior level candidates with 4+ years of QA experience

RESPONSIBILITIES:

• Own quality throughout the full feature lifecycle — from requirement review and test planning through exploratory testing, regression, release validation, production monitoring, and continuous QA process improvement
• Design and execute comprehensive test strategies covering web application flows, REST APIs, permissions, edge cases, failure scenarios, and non-functional quality standards
• Independently investigate production issues using browser developer tools, API inspection, logs, databases, and monitoring tools, clearly documenting and communicating defects with sufficient technical detail for engineering teams to act quickly
• Integrate automated tests into CI/CD pipelines and contribute to improving engineering processes that detect defects earlier in the development lifecycle
• Collaborate cross-functionally with Product, Design, Frontend, Backend, and Infrastructure engineers, acting as a true engineering partner in product development rather than a final testing checkpoint

REQUIREMENTS:

• 4+ years of full-time professional experience in Software QA, Quality Engineering, or Software Testing
• Strong experience testing modern web applications across complex user flows, permissions, edge cases, and failure scenarios, with hands-on REST API testing experience (Postman or equivalent)
• Solid test design skills — ability to convert product requirements and technical specifications into structured test scenarios, test cases, and risk-based test plans
• Experience owning regression testing, release validation, and go/no-go quality assessments for production deployments
• Fluent English required; Japanese is a plus

Nice to Have:

• Hands-on test automation experience using Playwright, Cypress, Selenium, Mabl, or similar frameworks
• Working knowledge of Python, JavaScript, or TypeScript for test automation and tooling
• Experience testing AI-powered products, generative AI workflows, or non-deterministic output systems
• Experience with performance testing tools (k6, JMeter, Locust) and observability tools (Datadog or equivalent)
• Familiarity with multi-tenant SaaS products, role-based access control, and CI/CD pipeline integration