I just completed a CS undergraduate at University A (top 50 rank for CS), and am taking a gap year after graduating. This past summer, I did an REU/summer research at University B (~top 15 rank for CS). I hope to get recommendations from professors within both universities, and I have been thinking of asking if there are any opportunities to gain extra research experience within the 1.5 years of gap year that I will have, hopefully to gain another recommendation that can speak with regards to my research ability.
Has anyone kept in touch with professors you've known since graduating, and how do people generally do so? I was thinking of asking one of the professors how I can best spend the gap year time that I have, but I was wondering if people maintain academic contacts like this after completing their undergraduate.