The topic is interesting, there is a lot of ground to cover, so this is all good.
I think there was not enough emphasis on the situations when you have a high number of events and the problems and approaches when you need to replay them to get to current state, yes snapshots have been mentioned, but I believe there should be more to say on that.
As for the delivery, Miro has a lot of mileage there, and it is nice to see the evolution of his speaking skill, but for some reason he was just a bit of his game. Still this was a great talk and you should really go see it
One of the most interesting talks so far, that yet again proves that time is relative.
Unless you really start looking into time and timezone related problems you usually have no idea how big of a mine field it is.
Andreas shed a nice light on the set of the potential problems you will encounter when working with time, especially with future dates.
This talk gave migraine and that is why it gets 5 stars.
Short talk, good questions
Great, light keynote. A good idea to say few words about PHP 7/7.1.
This was a nice overview of the systems out there, interesting topic and great delivery.
My only problem with this is using mongo as a reference for anything that is not a hobby project.