Stimming is using two octatrack mk2s in this performance. He described a desire to get rid of ableton and his APC40 in a 2015 interview with djtechtools, and it appears he's done it - no laptop here! Octatrack to artist's right is only connected on main outs, running into the inputs on the octatrack to artist's left. The SE-02 runs into the other set of inputs on the left octatrack, so that octatrack is also acting as the mixer. Stimming comments in the youtube comments, "The octa also works as a mixer. 2stereo Inputs - either through the whole engine incl fx or just to the Output on top of those other tracks. You can easily sample those Inputs anytime." In the end of the set, he describes the octatrack on his left as "the mothership playing the tracks without groove" and the octatrack on his right as "a groove sampler" and the SE-02 as "add on stuff" Stimming mentions that he uses 25 banks for the grooves in the grove sampler octatrack, and in the master "mothership" octatrack he only uses bank 1, pattern 1, and goes through the list of tracks. He says he will explain in detail how the setup works in another interview later this year with djtechtools.more
But once you get there it's a beautiful piece of kit. From what I read if you can work with the OT you will have no issues with other Elektron gear. If you already own a piece of Elektron kit it should be familiar and more easy to ramp up.