Literally just like everyone else who has posted so far. It's obvious that a company as large as Nationwide has completely standardized the interview process. There are no surprises. Sent resume via corporate website, received assessment link, took assessment, got a call a few days later for an interview. Went to interview, waited for the call a week and a half later. Accepted the job. Clockwork.
The interview was incredibly easy. It was very relaxed, and the two interviewers (one a hiring manager/supervisor and the other a "scribe" taking notes) were very personable. The questions asked were simple to answer thoroughly if you have any work experience and even a shred of personality. The STAR format thing is way overstated here, it was not expected that you answer in a very rigid or even structured way. They just want complete answers, not two word replies. Plus the obvious - make sure you prepare a variety of questions for the end. My interviewers were VERY thorough, and went over almost every detail of the work and company, so make your questions culture and behavior based, not basic yes or no things like "is there a 401k program"? I heard from other employees for the same position that most interviews are about 40 minutes, but mine was over an hour, so make sure to set aside at least that much time.
The main thing to know when interviewing for a company like Nationwide, especially this entry-level position, is that they want to hear that you're eager to learn and that you want to grow WITH the company. They're very concerned with culture, and they want you to be a part of the family and participate. If you are a person who wants to just go clock in and do a basic job at a mediocre quality level and clock out and go home, this will come across in the interview and it will be clear that you aren't a good fit. They're very big on promoting from within. That's no BS, it's genuinely their entire HR model. If you make it clear that you're hungry for knowledge and experience and that you want to move on and move up within the company, you'll probably have a job offer 1-2 weeks later.