It was a fun and interesting talk. One small tip: try to clean up your demo environment to make less mistakes.
Interesting talk on an interesting topic. I'dd love to see an in-depth talk about the configuration of both the application and logstash. What are you logging, why are you logging it, what kind of additional data can you log, ...
Great location, drinks, food and "Smurfen taart".
You managed to easily explain the basics of a complex system. I would love to see an in-depth talk about the server implementation.