Oh, what a ride! I got invited by friends from Łódź Ruby Users Group to give a speech. We made a deep dive into optimizations of Rails STI.

Slides are here: https://github.com/kampikd/kampikd/blob/master/slides/Turning%20Rails%20STI%20up%20to%20Eleven.pdf

More details here:
https://www.meetup.com/pl-PL/lodzrug/events/265208427/