Software Engineer (Go / TypeScript / AI-Driven Development)

About the Role We are looking for a versatile Software Engineer who prioritizes foundational engineering principles over ephemeral frameworks. In this role, you will leverage Go and TypeScript to build resilient systems while actively adopting cutting-edge, AI-driven development methodologies. You thrive in an autonomous, high-ownership startup environment, balancing independent execution with clear, proactive communication across a diverse team. Responsibilities Design, build, and maintain high-performance, reliable systems primarily using Go and TypeScript. Explore and integrate AI-assisted development tools and workflows to enhance team productivity and system capabilities. Collaborate on cloud and infrastructure architecture to ensure scalability and resilience. Take full ownership of features from technical conception to production deployment. Communicate transparently with cross-functional teammates, proactively identifying and removing blockers. Requirements Strong grasp of core programming concepts, design patterns, clean architecture, and computer science fundamentals. Hands-on development experience with Go and/or TypeScript. Self-directed and self-managing, with excellent collaborative and interpersonal communication skills (no siloed working). Strong passion for and curiosity about AI-driven software development. Passion for working in a fast-paced, iterative startup environment. Business-level Japanese proficiency (capable of handling technical alignment and cross-team communication in Japanese). Nice-to-Haves Experience designing, maintaining, or operating cloud infrastructure (AWS/GCP), containers, and CI/CD pipelines. Practical track record of using AI tools (e.g., LLM APIs, Copilot, Cursor) within daily development workflows. Professional English proficiency or experience working in multicultural/multilingual environments (a strong willingness to learn and use English is also welcome). Experience architecting systems from scratch or scaling products through rapid growth phases. Remote Policy In-Office Policy: Optional weekly office days on Thursdays at our Shinagawa Station office (encouraged if you live within commuting distance). Retreats: Mandatory in-office attendance for company retreats a few times per year