Senior AI / Python Engineer

Role - Senior AI / Python Engineer

Duration - 6 months with very likely extension

Location - Hybrid, 2 days a week onsite in London

Brief -

Senior AI / Python Engineer to join a technology team building a new generation of intelligent, data-driven applications.

This is a hands-on engineering position combining Generative AI development with strong Python software engineering. You will take AI capabilities beyond prototype stage, developing reliable applications and services that can operate at scale within a production environment.

The Role

You will work across the full engineering lifecycle, helping to design, develop and support AI-enabled products and backend services.

Key responsibilities will include:

• Building production applications and services using Python
• Developing solutions using LLMs and Generative AI
• Creating RAG and semantic retrieval solutions over structured and unstructured information
• Developing intelligent workflows using AI agents and orchestration frameworks
• Building scalable backend APIs using FastAPI
• Implementing document processing, embedding and vector-search capabilities
• Connecting AI services with existing applications, databases and data sources
• Creating methods for testing and measuring the quality of AI-generated outputs
• Containerising and deploying applications into modern cloud environments
• Writing clean, maintainable and well-tested software
• Working closely with product, engineering and business stakeholders to deliver solutions into production

Technical Experience

We are particularly interested in engineers with strong experience across:

• Python, ideally within large-scale production environments
• FastAPI, Pydantic and asynchronous Python
• LLMs / Generative AI
• RAG
• AI agents / agentic systems
• Embeddings and semantic search
• Vector databases
• PostgreSQL
• Docker and Kubernetes
• Modern CI/CD practices
• API and microservice development
• Automated testing and software engineering best practices

The Ideal Candidate

This would suit somebody who sits between a traditional Senior Python Backend Engineer and AI Engineer.

You should be comfortable building the underlying software around AI models rather than focusing purely on experimentation or data science. We are particularly interested in people who have taken LLM-based applications from concept through to a live production environment. This is a senior hands-on role, so you should be comfortable making technical decisions, solving complex engineering problems and working independently while collaborating closely with the wider technology team.

Why this role?

This is an opportunity to work on AI products where Python engineering, GenAI and production delivery are equally important. You will have significant involvement in how the solutions are designed and built, rather than simply integrating pre-built AI tools.

GCS is acting as an Employment Business in relation to this vacancy.