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Machine Learning Engineer, Platform

scaleai · London, UK · Full-time

About this role

Machine Learning Engineer, Platform

London, UK

Scale GP (Scale Generative AI Platform) is an enterprise-grade Generative AI platform that provides APIs for knowledge retrieval, inference, evaluation, and agentic workflows. We are looking for a Machine Learning Engineer to join our team and build the retrieval and knowledge representation systems at the heart of the platform. You will own ML components end to end — from research and prototyping through to production deployment — working across knowledge bases, vector stores, RAG pipelines, and context engines to power agents that deliver real impact for enterprise customers. 

You will:

• Own large areas of platform end to end, driving components from design through to production deployment.

• Work on knowledge representation systems, including ontologies and knowledge graphs, to support structured reasoning over enterprise data.

• Design and implement RAG pipelines, including chunking, embedding, indexing, retrieval, and reranking.

• Build and maintain integrations between retrieval and ML components and diverse enterprise data sources, vector databases, APIs, and services.

• Develop context retrieval systems that balance recall, precision, latency, and cost.

• Build evaluation frameworks, datasets, and metrics to measure retrieval quality, context relevance, and end to end agent performance.

• Build reliable backend services and data pipelines that support ML and LLM components in production.

• Deliver experiments and new capabilities quickly, maintaining high quality and tight feedback loops with customers.

• Collaborate across product, ML, and infrastructure teams to shape the direction of the platform.

Ideally you'd have:

• 5+ years of experience building and deploying machine learning or AI systems for real-world, production use cases.

• Strong engineering fundamentals, supported by a Master’s or PhD degree in Computer Science, Machine Learning, AI, or equivalent practical experience..

• A deep, hands-on understanding of retrieval systems, RAG, embeddings, vector indexing, and knowledge representation.

• Experience with knowledge representation, semantic search, or agentic systems.

• Proven proficiency in Python, including writing production-quality, testable, and maintainable code.

• Experience scaling or shipping products at high-growth startups.

• The ability to operate in ambiguous problem spaces, balancing research-driven approaches with pragmatic product constraints.

• Strong communication skills and comfort working in customer-facing or cross-functional environments.

PLEASE NOTE:  Our policy requires a 90-day waiting period before reconsidering candidates for the same role. This allows us to ensure a fair and thorough evaluation of all applicants.

About Us:

At Scale, our mission is to develop reliable AI systems for the world's most important decisions. Our products provide the high-quality data and full-stack technologies that power the world's l

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