First phase is with HR representative, they care about 'who' they hire as to be a good personality fit for the company. They are primarily looking for people who enjoy a flexible schedule, relaxed culture and are willing to work hard everyday to complete projects. Second (could be same day or on a follow up day) comes a technical meeting with the UX Director, who will go into what you have done and into your skills for the job.
You should prepared to answer any general and advanced javascript/object oriented questions, not very difficult because they are trying to understand that you have good critical thinking skills and are knowledgeable in most javascript concepts. You should be honest if you 100% don't know something then be honest about it because it shows that you are personable. It is also important to know medium to advanced CSS (preferably with a focus in object oriented CSS like SASS), make sure to understand HTML concepts including everything around post/get. Make sure to practice your JSON. If you get a chance to speak make sure to be willing to show you are interested in learning more around javascript frameworks (angularjs a big plus).
If they like you they will call you back to meet 1:1 with all the managers (one by one) to get to know you and figure out if you are a good fit for the company, make sure to be personable, to elaborate on all questions you're asked, to let them lead the interview while also asking them anything you want about the company. Emphasize in wanting to know all things Sharecare and also on their point of view. At the very end you will meet your potential new team members and get a chance to talk to them one last time before you leave. You will have to wait until you get a notification from HR that you have been accepted/declined, since it is a joint management decision based on your 1:1 with them. If you manage to get to that phase is because your potential future team likes you and have pushed forward for it, so don't be nervous nor too cocky, but be confident that you're about to land it nevertheless.