LinkedIn is a great source of information to do with colleges, companies, and employees. here are a few examples of the type of data you can collect (definitely not exhaustive).

Note: LinkedIn is very anti-scraping and you can very easily get your account blocked if you attempt it.

Example 1: Collecting data on college alumni (and where they now work)

Example 2: Collecting data on company alumni (and how many of them are now CEOs)