Senior Java Software Engineer (AI Integration)

About the role

Leyton CognitX, the AI & Tech Advisory of Leyton, is looking for a seasoned Senior Java Software Engineer to design and build production‑grade applications while integrating advanced AI capabilities. You will work on internal projects and client assignments, delivering intelligent solutions that meet strategic business objectives.

Key responsibilities

• Design and develop end‑to‑end features, including APIs, business logic, unit and integration tests, and deployment pipelines.
• Build and maintain robust, versioned, secure REST APIs and ensure scalability and security of production systems.
• Integrate large language models (LLMs) such as OpenAI, Anthropic or Mistral via APIs, managing tokens, cost and latency.
• Develop Retrieval‑Augmented Generation (RAG) pipelines, including chunking, embedding, vector stores and retrieval components.
• Mentor junior engineers, conduct code reviews and contribute to architecture decisions.

Required profile

• 3–5 years of professional software development experience.
• Strong Java/Spring Boot expertise and ability to work with Python or Node.js/TypeScript for client projects.
• Hands‑on experience integrating LLMs into production applications.
• Proven ability to manage multiple projects, prioritize tasks and communicate effectively with clients.
• Curiosity about applied AI and sound judgment on when to use AI components.

Required skills

• Java, Spring Boot
• Python, Node.js, TypeScript
• REST API design, versioning, security
• CI/CD pipelines, Git, SonarQube
• LLM integration (OpenAI, Anthropic, Mistral)
• LangChain, LangGraph
• RAG pipelines, vector stores, embedding

What we offer

• Professional development and career advancement within a growing organization.
• Participation in large‑scale projects across more than 18 countries.
• Collaborative, challenging work environment with brilliant colleagues.
• Modern office equipped with cutting‑edge technologies.
• Access to the latest AI tools and technologies.