Charlie Hull, a search expert and the founder of Flax, dives into the world of data-driven search optimization. He discusses the challenges of measuring relevance in search, emphasizing its subjective nature. Common pitfalls in search assessments are highlighted, including overvaluing speed and user complaints. Hull shares effective methods for evaluating search systems, such as human evaluation and user interaction analysis. He also explores the balancing act between business goals and user needs, and the crucial role of data quality in delivering optimal search results.