The role of a product manager in technology project lifecycles is to guide the development of a product from conception to launch. They are responsible for defining the product vision, identifying market needs, and prioritizing features based on customer feedback and business objectives. Product managers act as a liaison between different teams, including engineering, design, and marketing, ensuring alignment and effective communication. By overseeing the entire lifecycle, they help navigate challenges and ensure that the final product meets user expectations and achieves business success.