What is the purpose of a second interview?
A major reason for the second interview is so the employer can see how well you fit in with the company culture. Realize that the interviewers at your second interview want to learn how well you will get along with other team members with whom you'll be interacting every day.
What can I expect from a second interview?
Potential questions for a second interview
How long should I wait to follow up after 2nd interview?
Then, the waiting game begins. As a rule of thumb, you're advised to wait 10 to 14 days before following up. It's not uncommon to wait for a few weeks before hearing back from your interviewer. Calling too often can make you look needy and high maintenance.