# [2019.09.16] RecSys 2019

My main goal of coming to Copenhagen was taking part in an
international conference on recommender systems. I completed my
registration and received my badge yesterday, and today began with
the first keynote.

I was quite lucky to live in the same hotel which hosted the event
itself since some people needed to come here from somewhat distant
locations. Nevertheless, I woke up at 6:15 AM and succeeded not only
to have breakfast but also to go to the Frederiksberg Rådhus, get a
bike and ride it around the district a bit.

The keynote was surprisingly good, albeit not being technical. The
speaker drew parallels between collaborative filtering and
behaviourism in psychology. And that is a remarkably important
observation, I think. When building a recommender system, we try to
guess (or even to manipulate) user's behaviour, not preferences.
User's preferences usually stay dark even for the user herself. We
never are on the side of a user while creating recommenders and it
would be pretentions if not intentionally obscurant to state
otherwise.

There were many other interesting talks, as well. In the evening I
rode a bike to Tivoli Gardens where a welcome reception took place.
During the party, I befriended a Belgian guy and two girls, Norvegian
and Russian, all of them creating recommender systems, of course.
Talking to them, I realised that GDPR makes working with data much
harder. However, I still think we would better have such kind of
regulations in Russia too, instead of blocking Telegram and LinkedIn.
Our adventurous team even took a ride on a roller coaster named
Demon. Hail to brave demon riders:)

After the reception, I walked back to the hotel alone. Frederiksberg
is a pretty quiet place at night.