I go maybe a step further: I send out project-specific surveys that have things like impact metrics (How significant has the impact of Project X been, in terms of dollars, hours of effort, or deals won), classic NPS type questions (If a similar situation arose in the future, how likely would you be to reach out to me/my team for help?), and questions that dive into how the project went, how it was organized, and more.

I really should turn that into a business now that I think about it.