I remember going back in 2015. Biggest thing I remember were the "Smart" fabrics that would be integrated into your clothing for interacting with your devices. It was a cool demo but felt very silly and impractical.

I enjoyed the silent disco and free concerts, but it felt very over the top and expensive, basically just a big ego display for Google.

I can understand now why my company is less eager to send developers to events like these every year.