User research is not a “one-and-done” phase in the product development timeline. Keeping a direct line of sight to customers through varied user research methodologies is critical in being a successful product manager. Whenever you start in a new role, one of the first questions you should be asking is how to get data or how to connect with the people in the organization that have direct line of sight to users.
Early on in the product life cycle user research will be used to understand your customer target market, their needs, the core product features, and the priority for shipping these features. All of this will be completed in the envisioning phase as the product is being defined, then you will take it back and validate with customers.