Why did you decide to come back in Kyiv?
Because I've had a lot of fun at RubyC 2015 and I had wonderful time in Kyiv overall.
Name the brightest episode for Ruby/Rails in 2015?
My RubyC 2015 presentation, of course! :-) On a more serious note - I think 2015 was a relatively quiet year for Ruby, with Opal's significant progress being the brightest and most promising Ruby development as far as I'm concerned.
What is your prediction for Ruby and Rails?
I don't expect any interesting changes in Ruby this year. We'll probably get a small 2.4 update for Christmas, but the major changes will land in a few years with Ruby 3.0. As far as Rails is concerned - Rails 5 will bring a lot of interesting things to the table. I'm excited to see how things are going to play out after its release.
Who is better than Ruby?
I'd say that Clojure, Elixir and Go are Ruby's most interesting opponents these days. Rubyists should pay them close attention and ideally spend some time playing with them - they might end up learning a new trick or two.
Can one learn from “15 minutes” videos?
They are little more than a publicity stunt - they get people excited about something (which is good), but they don't properly teach people anything (which is not that good). I don't like such videos, but I acknowledge their usefulness.
Where will Ruby end?
Ruby will end in a long time in a galaxy far far away! May the Source be with you! :-)