I applied in-person. The process took 2 days. I interviewed at National Instruments (Austin, TX) in Jan 2018
Interview
Two-days in total. It started with a presentation for a group of about 15 people. It then progressed to individual interviews, heavy on technical, but fairly simple. I also met with the CEO and VP R&D.
Interview questions [1]
Question 1
Determine the gain of an amplifier circuit, and show your work.