Well, here's my two-tier. Incomplete and in use! 'Olympian' cuz it looks like the podium for Olympic medal winners to be photographed.
Single pump. Propane Boil & HLT. Electric RIMS Mash. PID control to be installed.
My nephews kinda rushed us into brewing their Oatmeal Stout recipe called 'Bubonic Stout'. (I'll get into that some other time) So it was rush some wiring, rush some paint, rush some switches, rush some propane plumbing..... and go for it!
Then it was, "oh crap! we need more heat shielding here. and here. and here." and, "Dang those QDs get hot with boiling water thru them!" and, "Dang. another leak." and , "Guess I should not have primered UNDER the hi-temp paint!" (as it all peals/burns off)
The brew turned out mighty fine and no one got electrocuted! (so far) Will carbonate in a couple weeks.