Senior Individual Contributor

This role leads the design and implementation of an AI-centered software development environment, including harness engineering that enables AI agents to develop software autonomously. Responsibilities include fundamentally rearchitecting STORES products with AI, building and improving AI-agent development infrastructure and tools, improving existing product functionality, launching new products, and serving as a technical or team lead. The role begins with understanding current products, systems, and architecture, identifying challenges created by an AI-first approach, creating and executing a roadmap with the VPoE and senior engineers, and forming project teams when needed.

Applicants must have at least five years of web application development and operations experience. Required experience includes leading development across multiple technical areas from infrastructure through applications, leading broad development processes from planning and design through operations, delivering high-difficulty projects, communicating accurately with internal and external stakeholders, involving the organization in project execution, and defining goals and leading teams or projects in environments with many changing factors.

Preferred experience includes using AI in software development, developing applications with multi-agent AI, practicing harness engineering, developing and operating AI products, building AI-agent software development environments, and creating major system-wide or business-wide transformation from a software engineering role.

The named environment includes Ruby, Ruby on Rails, Java, Spring Boot, Go, AWS, Google Cloud, Cloudflare, RDBMS, MongoDB, Terraform, React, Vue, Next.js, Nuxt, React Router, Swift, SwiftUI, Kotlin, Jetpack Compose, Xcode Cloud, Bitrise, Claude Code, and an internally developed AI agent based on the Claude Agent SDK. Google Workspace, Slack, Notion, Cursor, GitHub Copilot, Claude, Gemini, and ChatGPT are also cited. STORES develops digital infrastructure and products for local businesses, including online stores, POS, cashless payments, reservations, and AI business-support services.

The position is full-time in Tokyo with annual compensation of JPY 8,000,000 to JPY 15,500,000. Remote work is available, with at least two office days per month generally required as of May 2026; teams may set additional rules. Working hours use a flextime system with core hours from 12:00 to 16:00 and standard working hours of eight hours. The probationary period is three months under the same conditions. Benefits and leave include purchase assistance, training and conference support, book-purchase support, peer bonuses, vaccination assistance, childcare support, and several specified leave programs. The selection process consists of document screening, one or two interviews, a human-resources meeting and final interview, followed by an offer meeting.