What is a QA Engineer at Mercari?
At Mercari, the QA Engineer plays a pivotal role in maintaining the integrity, speed, and reliability of Japan’s largest customer-to-customer (C2C) marketplace. Because Mercari handles millions of transactions daily—incorporating complex listing flows, shipping integrations, and secure payment processing (such as Merpay)—the quality assurance team is the ultimate guardian of user trust. A bug in production doesn't just disrupt an app session; it can directly impact a user's financial transaction or physical shipment.
As a QA Engineer, you will not simply execute test cases; you will act as a strategic partner to product managers and software engineers. You will design comprehensive test strategies, advocate for user-centric design, and build automation frameworks that support continuous integration and rapid deployment cycles. The role demands a balance of deep technical execution, rigorous system analysis, and a strong understanding of consumer behavior.
Working in this position means navigating a highly dynamic, cross-border engineering environment. Whether you are optimizing the mobile application experience for iOS and Android or validating robust backend APIs, your contributions will directly influence how millions of global users buy and sell items every day.

