AI Full Stack Engineer
Summary
A 9-week on-site contract in London (Fenchurch Street) for an AI/ML Full Stack Engineer building multi-agent LLM systems: Python REST APIs using LangChain, LangGraph and Google ADK with OpenAI/Gemini/Claude, plus AWS OpenSearch vector search, cloud CI/CD, and LLM observability. Rate £291 PAYE / £388 Umbrella (per day).
Job Overview
Role: AI Full Stack Engineer (AI & ML Engineer)
Location: Fenchurch Street, London
Duration: Oct 12, 2026 - Dec 15, 2026 (9 Weeks, 2 Days)
Hours: 40 hours/week
Rate: 291 PAYE / 388 Umbrella
Core Technical Stack
Programming & APIs: Python, RESTful API development, JSON Schema, Pydantic.
AI & LLMs: Gemini, OpenAI, Claude.
Frameworks & Orchestration: Google ADK, LangChain, LangGraph.
Data & Search: AWS OpenSearch (Indexing and Vector embeddings - Highly emphasized), Database Architecture (Intermediate).
Infrastructure: Public Cloud (GCP, AWS, or Azure), containerization, CI/CD pipelines.
Key Responsibilities
Agentic Systems: Build multi-agent, stateful, and asynchronous workflows.
LLM Management: Handle prompt engineering, context/memory management, hallucination controls, guardrails, and fallback logic.
Observability: Implement tracing and evaluation frameworks, specifically utilizing LLM-as-a-Judge patterns.
Backend Engineering: Develop secure Python APIs and maintain strong testing and deployment disciplines.