When participants exit a session, can I have them answer a satisfaction survey?

Yes, this is possible. In the branding section, you are able to define an exit URL for meeting speakers and participants.

You would need to choose a URL where you have a set of survey questions hosted. When the session ends, each attendee will be redirected there.

Note: In order for this to work, the participant needs to choose the leave the session action in Digital Samba. If they close the meeting's browser or tab, they won't be redirected to your survey.