My experience was the same as most of the other comments on how Microsoft does interviews and hiring for internships. The process includes an online application, a phone interview, an onsite interview, and offer.
Immediately given white board and asked to solve coding prob. Interviewer described the problem and helped along the way. After, interviewer asked if I had any questions and that was it
I applied through college or university. The process took 1 week. I interviewed at Microsoft (El Paso, TX) in Sep 2019
Interview
Process was neither too quick nor too long. Employers were mostly interested in how you solved coding problems, so they gave enough time to solve them while the regular interview was short.
Interview questions [1]
Question 1
Tell about your most challenging project and how did you solved it?