Callum Macpherson
RSS FeedI'm an AI engineer in London. At Runna , I build the ML systems that make millions of people healthier runners. Before that, I spent time at AWS helping customers ship custom AI — from post-trained LLMs and autonomous agents to computer vision pipelines — across robotics, finance, healthtech, aviation, and more. I've worked with every modality you can throw at a GPU: video, images, audio, text.
I write about the engineering that gets models from notebook to production: retrieval systems, voice agents, evaluation frameworks, and the deployment details nobody warns you about.
Recent Posts
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Advanced Retrieval for Retrieval-Augmented Generation
Query expansion, cross-encoder re-ranking, and embedding adaptors for improving RAG retrieval quality.
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LLMs Evals: A General Framework for Custom Evaluations
A general framework for building rule-based and model-graded evaluations for LLM-based applications.
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Implementing RAG in LangChain with Chroma: A Step-by-Step Guide
A step-by-step guide to building a Retrieval-Augmented Generation system using LangChain, Chroma, and OpenAI embeddings.
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Malicious LLM Prompt Detection in Python
Building a malicious prompt detector using traditional ML classifiers in sklearn, trained on Deepset's prompt-injection dataset.