4.5 Hour interview with a 40min presentation up front about personal project. Interview was quite in depth but all fairly reasonable. The actual research team was lovely to talk to and the interview flew by. Even without an offer, it was good experience. Thw downside comes from hiring managers. They couldn't be bothered to offer feedback or even a short rejection notice. After demanding such a large amount of prep work and an entire half a work day, failure to contact applicants about outcomes both positive and negative is absolutely unacceptable and downright rude. Followed up twice as instructed by interview team and no response either time.

My experience with NREL was the worst (by a mile) that I've had in my career. The interview itself was fine. The problem was that almost 6 weeks after the interview, I was told that they didn't have the budget for the position. During those 6 weeks, the communication was very poor. I was told several times that they were very interested in hiring me, but there was no transparency as to the budgeting concern until the end. The process was one 3-hour interview, which began with a 30-minute presentation to the hiring group, which consisted of 8 engineers and the hiring manager, followed by three small group interviews.