• Design, implement, AI services and data infrastructure that are scalable, performant, maintainable, and secure • Architect (and re-architect) GenAI systems that push the boundaries of latency and scalability • Promote operational efficiency by establishing benchmarks in software design, implementing automated testing, and observability mechanisms • Serve as a feedback giver to teammates on their system designs and code quality • Use AI coding assistants and tools to implement your vision and magnify your impact • Collaborate with team members from diverse domains: product, data, and science • Provide leadership that helps navigate the team through complicated technical challenges • Support the growth and development of individuals and the team through interviewing, onboarding, and mentorship

• Serve as a primary developer for Perc Ultra SMP (32‑bit) and Perc 64 (64‑bit) • Plan and execute development tasks; troubleshoot issues and clear blockers • Implement bug fixes, feature enhancements, and major new release content • Develop and maintain regression tests for fixes and new functionality • Review, test, and approve code changes from team members before commit • Collaborate with Developer Tools leadership to maintain and update licensing components • Work directly with customer engineering teams to diagnose issues, resolve technical questions, and advise on best practices

• You will be challenged with developing features for the flea market app "Mercari," the smartphone payment service "Merpay," and the cryptocurrency/blockchain service "Mercoin" within Japan. • You will join a team of software engineers with diverse backgrounds and expertise and take on responsibilities as a team member. • You will be involved in projects aimed at improving the user experience (UX) and specifications from the customer's perspective for Mercari, Merpay, and Mercoin. • You will engage with the technology and data firsthand and produce tangible outputs. • Ultimately, you will present your work and actual results at a final report meeting. • During this internship, you will work to develop actual features integrated into the app and to improve the operation of the app. • At Mercari Group, you will be able to take on bold challenges without any fear of failure. What’s more, you will be able to flexibly choose the latest and optimal technologies, and because we foster an environment and culture that supports independent decision-making, the experience will offer an opportunity for both personal and professional growth.

• Design, develop, and maintain full stack features using Node.js, React.js, and Next.js • Build and optimize backend services and APIs with Node.js • Work with PostgreSQL to design schemas, write efficient queries, and improve performance • Develop responsive and performant frontend applications using React, Redux, and Redux-Saga • Collaborate with cross-functional teams to understand requirements and deliver solutions • Write clean, maintainable, and well-tested code • Participate in code reviews and contribute to engineering best practices • Debug, troubleshoot, and resolve production issues