ur client, a big global media entity, entrusted us with managing their vast trove of advertising, sales, and audience data, spanning billions of rows. This raw data, subject to frequent updates and modifications, demanded meticulous modelling into a semantic layer to serve a multitude of consumers, including a SaaS product tasked with generating insights on audience segmentation. Each update presented a myriad of challenges, from changes in unique identifiers to the introduction of new datasets, necessitating constant adaptation and optimisation of the semantic layer. Guided by the imperative of maintaining optimal performance, we engaged in rigorous benchmarking, testing, and gap analysis, striving for continual enhancement with each iteration.