The client is one of Japan's fastest-growing AI companies, trusted by over 8,000 enterprises worldwide. Backed by more than $200M in funding from top-tier investors and partnered with OpenAI, they are building next-generation AI products powered by LLMs, intelligent agents, and search technologies.
They are now looking for a Senior Software Engineer to own the architecture and development of mission-critical search, recommendation, and AI agent platforms that power their enterprise SaaS products. In this role, you'll design and build highly scalable search and recommendation systems, integrate LLM-powered capabilities into enterprise products, improve production performance and reliability, and collaborate closely with Product Managers and cross-functional engineering teams to deliver AI-driven user experiences. Beyond implementation, you'll mentor engineers, drive technical decisions, and contribute to broader product development across the platform.
What they're looking for:
- 5+ years of software engineering experience
- Experience building or operating search systems (Elasticsearch, Lucene, Solr, search APIs, indexing pipelines, etc.)
- Strong Python development experience
- Experience building scalable backend systems
- Experience with AWS, Google Cloud, or Azure
- Knowledge of data structures and algorithms
- Business-level Japanese (JLPT N2 or above)
- Passion for leveraging AI-powered development tools and modern engineering practices
Nice to have:
- Experience with LLMs, AI Agents, LangChain, LlamaIndex, RAG, or similar technologies
- Machine Learning or NLP experience
- Experience mentoring engineers or leading technical projects
- MS or PhD in Computer Science or related fields
- Business-level English
- Experience contributing across multiple product domains
What's on offer:
- Salary up to ¥20M
- Work on cutting-edge AI, LLM, Search, and Agent technologies
- Access to the latest AI development tools including ChatGPT Enterprise, Claude Code, Cursor, GitHub Copilot, Devin, and Codex
- Full-flex working hours with a hybrid work environment in Shibuya
- Visa sponsorship available
- Employee stock ownership program
- Strong learning budget for books, certifications, and professional development
- Opportunity to join one of Japan's leading AI engineering organizations shaping the future of enterprise AI products
Apply now!