The practice of representing the customer's perspective within quality and engineering teams, going beyond verifying acceptance criteria to ask whether a product can genuinely be used by real people to achieve their goals. A quality professional practicing customer advocacy develops deep familiarity with how different customer types interact with the product, including non-technical users, and uses that knowledge to evaluate whether features make sense, flow naturally, and hold together as a coherent experience. This goes beyond checking that something works and asks whether the right thing was built in the right way for the people who will use it.For example: validating that terminology is consistent across a product built by multiple teams; observing real customer training sessions to understand where frustration occurs; or testing a feature against known customer setup patterns rather than a single idealised scenario.