Software Engineer

This is a full-stack Software Engineer role on Sakana AI's Product team, based in Tokyo, building the company's in-house AI products end to end. Responsibilities include full-stack design and implementation covering the frontend (React/Next.js), backend APIs, databases, and cloud infrastructure; building and operating the production platform including CI/CD, monitoring, scaling, and security; integrating ML/AI models into products by working with Applied Research Engineers on LLM inference, memory systems, and search algorithms; and running a fast development cycle from hypothesis to prototype, validation, and improvement with the Product Owner. The role involves collaborating in an international team that works in both Japanese and English. Requirements include 3+ years of practical experience as a Software Engineer in production, full-stack development experience, experience designing and releasing user-facing products, autonomous development experience in a small team, practical experience with Python and a modern web framework, and experience with Docker and cloud platforms. Experience with AI/ML model serving and inference optimization, DevOps/Infrastructure as Code, or working at an AI/ML startup is preferred. Employment types include full-time, contract/freelance (minimum 24 hours/week), and internships (minimum 2 months, 24+ hours/week). Candidates are expected to be based in Tokyo; visa application assistance is available if needed. Japanese (conversational) and English (business) are required, and the CV/cover letter must be submitted in English.