Senior AI Engineer (Agentic AI / Python Backend) - Freelance

Senior AI Engineer (Agentic AI / Python Backend)

Target: Senior Python backend developer who has delivered AI agents in production, ideally with experience in ontologies and knowledge graphs.

Context: Our AI (Engineering) team builds the AI features embedded in our SaaS platform, in an international environment. We are looking for a senior consultant to strengthen the team. The consultant will report to the Head of Data & AI.

Key responsibilities

• Design and develop the backend components of AI features (SaaS and on-premise) running in production.

• Build AI agents: multi-agent systems, workflow orchestration and LLM-driven reasoning.

• Develop MCP servers and custom tools that connect agents to applications, APIs and databases.

• Design RAG / Agentic AI architectures based on vector databases, knowledge graphs and ontologies.

• Set up an AI gateway (such as LiteLLM) for model routing, governance and cost control.

• Implement observability and evaluation for AI services (OpenTelemetry, LangSmith, Langfuse…).

• Mentor junior developers and help shape AI engineering best practices.

Must-have skills

• Python / FastAPI: expert level, REST APIs, microservices, asynchronous programming.

• Generative AI in production: significant, proven experience (not only POCs).

• LangChain / LangGraph or equivalent, multi-agent systems.

• MCP (Model Context Protocol) and A2A (Agent-to-Agent).

• RAG: vector search, embeddings, context optimization.

• Ontologies / knowledge graphs: business domain modeling and semantic reasoning. This is the core requirement for this role.

• OpenTelemetry, Docker, CI/CD, Git, testing (pytest).

• SQL (SQL Server, MySQL) and vector databases (Elasticsearch or equivalent).

Nice to have

• Neo4j or another graph database (strongly preferred)

• LiteLLM or another LLM gateway

• LangSmith / Langfuse / Arize Phoenix

• GKE / Google Cloud

Profile

• Senior backend developer with real expertise in agentic AI, autonomous and able to contribute quickly.

• Strong communicator, comfortable working in English with international teams.

• Able to mentor junior team members.

Practical information

• Start date: ASAP

• Location: Puteaux (hybrid model – 2 days work from office)

• Languages: French / English