Through the Los Alamos Summer School, I had the opportunity in January/February 2016 to work as a guest researcher at Chonbuk National University in Jeonju, South Korea. I was only able to be in the lab for a month, but I was able to design, build, and test a high voltage signal conditioner and amplifier for piezoelectric sensors.
This was the largest PCB I have ever designed at about 20 x 30 cm and consisted of 10 individual amplifier channels. Each channel had an input BNC and output BNC as well as a gain knob. It was so large I had to learn a new design tool (Kicad) as Eagle was limited in size.
The PCB was designed to fit into an existing lab enclosure, and the lid was laser cut to allow the the BNC I/O and control knob.