Many READMEs, wiki pages, and other text-based documentation of the mongod exists. However, no definitive or illustrative diagram exists. At some level, having a diagram can explain interactions, layers, and components in the system. As the old adage goes, a picture is worth a thousand words. Cutting down the learning curve across the server provides many benefits to the org and company.

While this diagram doesn't need to be exhaustive or overly detailed, starting with a fairly high-level one would be a great start for full-timers, interns, and users alike.