Next we had some good lightning talks but those went too fast to pay both attention to and toot about.
After that Alexander Chatzizacharias showed a new approach to developing code by using the IntelliJ IDE as game engine that operates directly on one's code base.
By blowing up bugs, shooting dependencies and force pushing those changes to master you'll be more productive than ever!
Paco van Beckhoven had a really nice talk about good conventions around code reviews.
The final two presentations by Shirley Tarboton and @bert_hubert were nice complementary talks about respectively energy usage caused by our software development methods and actually inefficient software.
Bert had some seriously impressive graphs and examples on 1000x gains that can be made by focusing on making one's software more efficient.
If you're interested in any of these talks, AFAIK Joy of Coding puts these online every year.