An in-depth interview is a structured or semi-structured qualitative research method in which a researcher engages a single participant in an extended, focused conversation. The goal is to surface rich, nuanced insights that surveys and quantitative methods cannot capture, including emotional drivers, decision-making processes, and lived experiences. In-depth interviews are widely used across customer research, product development, brand strategy, and user experience studies. Because each session is tailored to the individual, researchers can probe unexpected themes as they emerge, making this method particularly valuable when exploring complex or sensitive topics at an enterprise level.