Customer engagement is the process of interacting with customers through various channels and strengthening relationships with them. It involves building a strong brand personality, understanding customer preferences deeply, providing great onboarding experiences, tailoring engagement strategies to the customer journey, personalizing customer experiences, gamifying engagement, creating feedback loops, and continuously experimenting and iterating for improvement. Autodesk, The Motley Fool, and Shortcut are examples of companies that have successfully implemented customer engagement strategies.