Software Engineer, Backend (foundation) - Mercari Marketplace

• Develop, maintain, and operate backend services in Go across the Foundation domain (notifications, user attributes, media).
• Investigate and resolve operational support and inquiry tickets raised by internal teams and Customer Support, improving reliability and reducing recurring toil.
• Join the on-call rotation after onboarding to support incident response for Foundation services.
• Contribute to platform initiatives such as the global rollout, growth-related initiatives, campaigns, enabling agentic SaaS-like experience for core services, modernization and rearchitecturing of legacy systems, and more.
• Write tests and documentation, and participate actively in code reviews.
• Proactively identify improvement opportunities in the team's services, code, and operational processes, and drive them through to implementation.

Unique Challenges

• Foundation services are used by almost all of Mercari; changes demand strong attention to reliability, scale, and backward compatibility.
• Balancing a meaningful operational/support load alongside feature and migration work requires good prioritization and communication.
• Contributing to a large-scale data migration that touches core user and notification data.
• Operating core services at very high volume such as notifications across various types and channels (InApp, push, email, SMS/Voice), where fan-out, delivery reliability, all have to load up under load.
• Working across several distinct domains and maintaining enough operational familiarity with each service to support and run all of them.

• Required Experience/Skills
• Backend software development experience (Go preferred; strong experience in another server-side language with the willingness and ability to learn Go).
• Solid understanding of designing, building, and operating web services / APIs.
• Familiarity with relational databases and SQL.
• Experience working in a cloud environment (GCP preferred) with containerized deployments.
• Operations experience with on-call and customer support.
• Preferred Experience/Skills
• Experience with distributed systems and microservices at scale.
• Experience with messaging/notification systems (push, email, SMS).
• Exposure to Google Cloud Spanner or large-scale data migrations.
• Experience with gRPC / Protocol Buffers and Kubernetes.
• Experience with CloudFlare Streams/Images.
• Experience with Amazon S3 and SES.
• Language
• Japanese: Welcomed but not required
• English: Business-level, working proficiency

Mercari Engineering Principles are a shared understanding that serves as the foundation of engineering beliefs and behavior at Mercari. The Engineering Principles are designed to complement the organizational identity (Mercari's mission, values, and culture) from an engineering viewpoint. These principles ultimately help us achieve Mercari's mission by defining the ideal state we seek to realize in the long term. * Passion For The Product * Grow Together * Solve Through Mechanisms * Collaborate Openly For More Details, Please See The Following Link * Engineering Culture The Foundation Backend team builds and operates the core business services that nearly every part of Mercari depends on, including notifications, user settings, and media.. These are high-throughput, business-critical systems written in Go on Google Cloud Platform. Our work ranges from day-to-day reliability and support of these services to large company initiatives such as platform globalization, growth-related initiatives, marketing campaign improvements, enabling agentic SaaS-like experience for core services, and modernization and rearchitecturing of legacy systems. We keep the foundation stable, scalable, and evolving so product teams can move quickly on top of it., At Mercari Group, we value empathizing with and embodying the mission and values of the Group and each company. To promote the creation of an organization that maximizes the total amount of value exhibited by all members, we would like to understand the experience and skills of each candidate as accurately as possible. Recruiting cycle at Mercari Group * Application screening * Skill assessment: For engineering positions, you will be asked to complete a skill assessment on HackerRank or GitHub. For non-engineering positions, you may be asked to complete an assessment depending on the position. (The timing of the assessment may coincide with the interview process.) * Interview: The number of interviews may vary depending on the position. * Reference check: We will ask for online references around the timing of the final interview. * Offer: Offers will be determined carefully in consideration of the final interview and the reference check. Learn more about our recruiting process here. Equal Opportunity Hiring Here at Mercari, we work to realize a world in which no one's potential is limited by their background and everyone has the opportunity to freely create value. We also firmly believe that a mindset of Inclusion & Diversity is essential for us to achieve our mission. This, of course, extends to our hiring practices as well. Mercari is committed to eliminating discrimination based on age, gender, sexual orientation, race, religion, physical disability, and other such factors so that anyone who shares our mission and values can join us, regardless of their background. For more details, please read our I&D statement. Please read and acknowledge our Privacy Policy prior to submitting your application. About Mercari 201-500 Tokyo, Tokyo, Japan Website