Full-Stack Java Spring Boot Developer (AI + LLM / RAG) – Remote

Location: Remote (strong English communication required) Project Base: US-based (Kansas City time zone alignment preferred for meetings) Type: Long-term hourly contract (part-time, ~20-30 hours/week) Rate: Competitive (trial period available) About the Project We are developing a modern SaaS platform for service-based businesses. The core feature is an intelligent AI system that handles customer interactions, answers questions, and manages bookings automatically. We use AI-assisted development (primarily Claude Code or Codex) to accelerate both frontend and backend work. About the Role Most of the development is done using AI tools, mainly Claude Code. Your role is to guide the AI, review the generated code, provide feedback, and refine both backend logic and frontend UI to production standards. ~80% of the work will be on the backend. This position is ideal for a full-stack developer who enjoys working with AI coding assistants and wants to focus on architecture, integration, and polishing the final result. Key Responsibilities Develop robust Spring Boot 3.x backend services using Java 21/25 Integrate LLM APIs (Anthropic Claude and/or OpenAI) Design and implement RAG (Retrieval-Augmented Generation) pipelines for business knowledge and accurate responses Work with LangChain4j to build reliable AI agents and conversation flows Build and maintain clean REST APIs for frontend and third-party integrations Review, refine, and polish AI-generated React/Next.js frontend code (TypeScript + Tailwind) Contribute to scalable architecture for AI-driven customer experience features Write clean, well-tested, production-ready code Requirements Strong Java + Spring Boot experience (3+ years) Hands-on integration with LLMs (Anthropic or OpenAI) Practical experience with LangChain / LangChain4j and RAG systems Solid React / Next.js skills (TypeScript, Tailwind CSS) Experience with RESTful APIs and modern backend development Good understanding of prompt engineering and AI agent patterns Strong problem-solving and clean code practices Comfortable working with AI coding tools (Claude Code, Cursor, etc.) Good English communication skills Nice-to-Haves Experience with voice or telephony integrations (Twilio or similar) Familiarity with vector databases Previous work on AI chatbots or customer automation systems Contract Details Long-term/ongoing project (more than 6 months) Hourly contract Work from home, but developers will remote login (via secure VPN + company-managed access) into a US-based development computer for all work Flexible working hours We will start with a small paid test task to evaluate the collaboration before moving forward with a longer-term contract. If you’re a full-stack Java developer excited about building production-grade AI systems using modern tools and AI assistants, we would love to hear from you! Please apply with relevant project links (especially any AI/LLM/RAG work) and your expected hourly rate.