Usability testing is a crucial step in product development, involving observing real users interacting with a product to identify potential issues and improve its design before launch. This process helps teams avoid releasing unwanted features by addressing cognitive biases and preventing the Dunning-Kruger effect, where developers might mistakenly believe they understand user needs without proper testing. Usability testing follows prototyping and includes setting objectives, recording hypotheses, outlining methods, conducting tests, and synthesizing findings. It can be conducted in-person or digitally, with each method offering unique insights, and often involves tasks like measuring how quickly users can accomplish goals or how satisfied they are with the product. By testing, teams gain valuable feedback directly from users, ensuring the product is both functional and appealing, ultimately increasing the likelihood of successful adoption and reducing the risk of failing to meet user expectations.