Senior Software Engineer Python / Agentic AI - Part-time - Banking sector - Freelance (M/F)

As part of the development of a data and artificial intelligence platform already used in production by several thousand users, a fast-growing organization in the banking sector wishes to strengthen its technical team.

The platform notably allows for the development and execution of data and AI workflows, the use of agents and RAG systems, the manipulation of several language models, and the provision of dedicated working environments for users.

After an initial phase primarily oriented towards internal use, the solution is entering a new stage of development with a progressive opening to external clients. This evolution raises important challenges regarding scalability, robustness, security, performance, and maintainability.

The team, composed of about thirty people, brings together Software Engineers, AI specialists, data profiles, and researchers. It is looking for a senior profile capable of providing perspective on existing architectures while remaining heavily involved in development.

OBJECTIVES AND DELIVERABLES

The consultant will act as a Senior Software Engineer with a technical architecture dimension.

They will notably:

• design and develop software components for the platform;
• develop backend services in Python, notably with Django or equivalent frameworks;
• contribute to the design and evolution of web applications in React and TypeScript;
• design APIs and integrations with data and AI components;
• participate in the development of agentic systems and orchestrated workflows;
• work on LangGraph, RAG, knowledge bases, MCP, and LLM application evaluation topics;
• contribute to the integration of several language models via a multi-model gateway;
• improve the scalability and reliability of the platform in a context of growing usage;
• challenge existing architectures, technical choices, and development practices;
• participate in the definition of robust, easy-to-maintain, and production-ready solutions;
• develop tests, technical documentation, and production deployment procedures;
• contribute to the observability, security, and governance of the developed components;
• collaborate closely with software, data, AI, and research teams;
• ensure hands-on involvement in the code and the delivery of components.

Required Skills

• Minimum 8 to 10 years of experience in software engineering, backend, or platform engineering;
• Very good mastery of Python;
• Experience with Django, FastAPI, or a comparable backend framework;
• Experience in web application and API development;
• Knowledge of React and TypeScript;
• Experience with Kubernetes, Docker, and cloud environments;
• Mastery of testing practices, CI/CD, software quality, and monitoring;
• Concrete experience with artificial intelligence systems in production;
• Knowledge of LLM, RAG, embeddings, or agentic orchestration;
• Experience with LangGraph, LangChain, or an equivalent technology;
• Ability to design, challenge, and evolve distributed architectures;
• Ability to work with multidisciplinary teams including engineers, AI experts, and researchers;
• Fluent professional English.

Preferred Skills

• AWS Bedrock, Azure OpenAI, or other cloud LLM platforms;
• LLM Gateway, multi-model routing, and quota management;
• MCP, tool calling, workflows, and multi-agent systems;
• Langfuse, LangSmith, RAGAS, or AI evaluation and observability tools;
• Trino, Dagster, Delta Lake, Superset or