Here's what people have asked and answered about working for and interviewing at Ultragenyx Pharmaceutical.
Keep doing exactly what you're doing. No need to fix something that isn't broken.
Its a fairly quick hiring process, depending on the position some may take a few days longer than others. Generally for all positions here you will be interviewed or talked to by about 2 people, once a decision is made, which generally takes them about a week tops, they get you in to on-board fairly quick. My own personal on-boarding experience was two days and then I umped right in with everyone else.