Recap of AWS Re:Invent 2022: An Honest Review of Announcements

"To solve the slow cold starts, AWS announced SnapStart for Java functions. In short, it initializes the Lambda function and saves the state in the memory, and restores it instead of doing the initialization again. This feature makes use of the Firecracker snapshot feature, and it has been promising for many users so far that it can drive down the slow start to 200 milliseconds from 6 seconds!"

SnapStart for Java lambda functions is the best announcement I heard about this year. It's a great feature and it was presented very well in the keynote, which showed their progress in eventually bringing startup time down to (basically) zero over several steps.