Workshops in tech you haven't yet used. Attendees are split into tables so you can talk and work with the folks at your table. You're given a quick overview presentation, a booklet to follow along with the exercises, and folks hover around the room to help unblock you if you're stuck. You visit a unique url and get a temporary aws environment spun up for you (previous years you were given credits for your own aws account but this is much better).
A few years ago I went to one which combined WAF, Athena and Sagemaker. It's great for all those "I should play around with that tech when I get some time" topics during the year where more often than not "some time" never comes.