Senior ML Engineer

Salary: £70,000-£90,000 Location: London (Hybrid)

We're looking for a Senior Machine Learning Engineer to help design, build, and deliver next-generation AI systems. You will work across LLMs, retrieval-augmented generation (RAG), and modern agent frameworks to transform large, unstructured data into meaningful insights and production-ready capabilities.

This is a hands-on role within a growing AI team, offering the chance to shape architecture, build scalable pipelines, and ship features that directly impact users.

• Develop, integrate, and fine-tune LLMs for natural-language understanding, reasoning, and workflow automation.

• Build agentic/LLM-driven workflows for multi-step decision making across diverse data sources.

• Architect and deliver ML features such as pattern recognition, entity extraction, and intelligent automation.

• Design scalable data and streaming pipelines capable of handling large, heterogeneous datasets.

• Build and optimize vector search, embeddings, and RAG systems to support high-quality retrieval.

• Deliver production-ready APIs, services, and model inference systems.

• Manage deployment, monitoring, observability, and continual improvement of ML models.

• Evaluate model performance using offline metrics, A/B tests, latency and cost optimisation.

• Work closely with product and domain experts to translate requirements into robust ML solutions.

• Strong proficiency in Python and experience with PyTorch or TensorFlow.

• Practical experience with LangChain, LangGraph, AutoGen, or similar LLM/agent frameworks.

• Skilled in prompt engineering, integrating foundation model APIs, and LLM fine-tuning techniques.

• Expertise in building RAG systems, vector databases (e.g., Pinecone, Weaviate), and embedding pipelines.

• Experience with ML/LLMOps for monitoring, evaluation, and traceability.

• Solid understanding of distributed systems, microservices, and real-time data processing.

• Comfortable with containerisation and cloud infrastructure (Docker, AWS, Terraform, etc.).

• Experience deploying production AI systems with a strong focus on reliability and safety.

• Background in NLP, information extraction, or large-scale unstructured data processing.

• Experience in security, intelligence, or data-heavy platforms is a plus but not required.

• Degree in Computer Science, AI/ML, or equivalent practical experience.

• Demonstrated experience building and shipping ML/AI products at scale.

• Proven track record working with LLMs, RAG pipelines, or agent-based systems.

• Hybrid: mix of remote work and in-person collaboration in our London office.

• Flexible schedule within standard business hours.

Oscar Associates (UK) Limited is acting as an Employment Agency in relation to this vacancy.

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