Machine Learning Engineer

Company: Oscar
Apply for the Machine Learning Engineer
Location: London
Job Description:

Overview

As a Machine Learning Engineer, you will own the ML layer of an enterprise-grade platform, from prototype to production. You will collaborate with a UK-based core team to build LLM-powered features, document intelligence pipelines, and retrieval-augmented generation systems for financial workflows. You’ll design robust evaluation regimes, guardrails, and production ML services that are observable and safe to fail. This role combines applied NLP/LLM work with high-stakes finance, in a multi-tenant SaaS context, offering a chance to shape reliable analytic products.

Responsibilities

  • Design, build and ship LLM-powered features and multi-step agent workflows in Python, from prototype to production
  • Develop document intelligence pipelines to extract and reason over complex financial documents
  • Create retrieval-augmented generation systems with embeddings, vector search, and citation tracking
  • Build evaluation frameworks and datasets with automated tests and human review loops
  • Implement guardrails and safe-failure behaviour; expose approvals and tool calls to users
  • Fine-tune and benchmark models, balancing hosted/open-weight models and classical ML for cost/latency/accuracy
  • Operate ML services and APIs with authentication and tenant isolation
  • Own MLOps in production including experiment tracking, versioning, monitoring, drift detection, and incident response
  • Write tests and ship through Jenkins and SonarQube to AWS
  • Collaborate with back-end/front-end engineers and domain experts to translate analyst workflows into reliable products

Key requirements

  • 5+ years in machine learning or software engineering with production ML experience
  • Hands-on experience shipping LLM-based/NLP systems (RAG, agents, tool use) and ability to justify design decisions
  • Rigorous evaluation approach with clear metrics and test sets
  • Strong grounding in ML stack (PyTorch, scikit-learn, Hugging Face, vector databases)
  • Experience deploying/monitoring models on cloud infrastructure (ideally AWS) with Git, CI/CD, and containers
  • Experience building SaaS or multi-tenant products with data security and access control understanding
  • Daily use of AI coding tools (e.g., Cursor, Claude Code) and ability to assess their utility
  • Degree in computer science/engineering/mathematics/statistics or related field, or equivalent experience; postgraduate valued but not required
  • Familiarity with production-grade software engineering practices and observability
  • clear communication of design decisions
  • ability to work with cross-functional teams
  • detail-oriented with a rigorous quality mindset
  • PyTorch
  • scikit-learn
  • Hugging Face

…

Posted: October 2nd, 2026