Software Engineer, Backend at Mercari

Setup: Hybrid
Location: Tokyo
Type: Full-time
Posted: May 26, 2026

Description

Mercari is seeking a full-time Software Engineer, Backend (Ops Foundation) to join their team. This role involves developing an AI knowledge platform to manage and utilize customer service knowledge, automating and optimizing inquiry response processes, and collaborating with stakeholders to define and implement technology strategies. The engineer will leverage large-scale AI systems to address real-world problems using data from Mercari's extensive user base.

Required Skills

Large-scale Web Applications
Scalable API Design
React.js
TypeScript
Public Cloud Systems
Google Cloud
AWS

Additional Information

Required Previous Experiences: 5+ years of experience developing large-scale web applications.
Experience designing, developing, and operating systems with scalability and maintainability in mind.
Experience designing and developing scalable APIs using modern languages such as Go.
Experience developing SPAs with complex state management using React, TypeScript, etc.
Experience developing and operating systems using public clouds such as Google Cloud and AWS.
Preferred Qualifications: Experience in system development using LLMs through to production deployment.
Understanding of CS operations, with knowledge of customer support workflows (receiving calls, ticket creation, escalation, etc.) and KPIs (response rate, resolution rate, etc.).
Experience in developing or operating and maintaining CS/call center-related products (CRM, FAQ systems, chatbots, etc.).

About Mercari

Mercari

Discover deals on everything from secondhand fashion to pre-owned collectibles, electronics, books & more on Mercari. Your go-to marketplace for hassle-free selling and deals.