Senior Fullstack Engineer (AI, RAG & Automation)

🎯 Role Overview
We are seeking an innovative Senior Fullstack Engineer (AI) to lead the charge in building, optimizing, and scaling our next-generation AI systems. In this role, you will bridge the gap between robust web architectures and bleeding-edge AI capabilities.We are looking for a developer who doesn't just write code but is highly passionate about researching new products and translating emerging AI trends into concrete business solutions.To succeed in this role, you must have a solid fullstack foundation, proven experience deploying practical AI systems (either through RAG or AI Automation Workflows) in live production environments, and a deep familiarity with the quality and delivery expectations of Japanese projects or companies.
🔑 Key Responsibilities
· Architect, deploy, and maintain end-to-end AI applications, leveraging either RAG architectures or complex multi-agent automation workflows.
· Build high-performance, secure backend services (e.g., Python/FastAPI, [protected info]) and clean, intuitive frontends (e.g., React, [protected info]).
· Actively research, benchmark, and prototype new AI models, developer tools, and automation frameworks to keep our product suite ahead of the curve.
· Work closely with product stakeholders and engineering teams to ensure that deliverables meet the rigorous quality standards typical of Japanese clients and businesses.
· Seamlessly integrate third-party APIs, vector databases, LLM orchestration platforms, and workflow automation engines.
✅ Technical Requirements
Core Technical Experience· At least 4 years of professional experience in Fullstack software development.
· At least 1 year in one of the following:o RAG (Retrieval-Augmented Generation): Experience building live RAG pipelines utilizing vector databases (e.g., Pgvector, Pinecone, Qdrant) and orchestration frameworks (e.g., n8n, LangChain, LlamaIndex).
o AI Automation Workflows: Experience designing and deploying autonomous AI agents, multi-agent workflows, or complex LLM-driven automation (using tools like n8n, Langflow, Flowise, or custom crew/agent frameworks).
Proven experience working within a Japanese company or delivering projects for Japanese clients. You are comfortable with the detail-oriented, systematic, and high-quality expectations of the Japanese business ecosystem.
You love tracking AI developments, reading research papers, and tinkering with new open-source tools. You are excited to recommend and build proof-of-concepts (POCs) for fresh product ideas.
WHY YOU WILL LOVE WORKING HERE
Competitive salary and benefits including Premium Healthcare package insurance
13th month salary, Performance bonus
16 days annual leave- Comprehensive Training Courses (Languages, Technical and Soft-skill)
Language Certificate allowance (TOIEC, IELTS and Japanese)
Lunch and bus/ parking allowance- Fun team activities and outings
Sponsored happy hour and sport clubs
Comfortable work space and friendly colleagues