I applied through college. It take around 2~3 weeks to get an email to take the online assessment for EECEs. It took 90 minutes to take. There was one problem to write a simple function in the end and you can choose the language you prefer. There were some questions related to the circuits and bits.

Talked to recruiter at college career fair. Didn't hear back from them until received an email with a test a couple weeks later. 90 minute test for EECEs. If you do well enough you are invited on campus for an interview day within 2 weeks. Interview day seemed more of a test of desire/fit. Asked questions more about why you are here,what you like. Some questions on coding logic, some PCB knowledge. Overall seemed more towards finding best fit rather than proving self. Interviewed with maybe 10 others, heard only a couple got offers. Interviewed with 4 different people, various get to know you conversations

They were collecting resumes during an on-campus job fair. After about a month, I received an email that invited me to complete an online skill assessment test. The assessment contained approximately twenty questions regarding electrical engineering and computer engineering. And there were two programming sections where your entered code was validated. The assessment could be considered somewhat challenging if you were never exposed to certain topics. Afterwards, you may be invited to a four-hour interview at the Irvine office. There was an orientation, one-on-one interviews with four separate employees, and a tour of your potential work site. During the interviews, you will be asked about your experiences and also several technical questions. But normally, the FIT-U engineers are only assigned to a few specific programs like Failure Analysis.