Signed NDA. But questions are focused on basic fundamentals that test your analytical skills and data structures knowledge.
Sigiloso
Through questions like this, interviewers are mostly trying to test your skillset (and its relevance to the role) as robustly as possible, so be prepared for multiple offshoots and followups. It could be a useful exercise to do mocks with friends or colleagues in Salesforce to get a real sense of what the interview is actually like. Alternatively Prepfully has a ton of Salesforce Senior Software Engineer experts who provide mock interviews for a pretty reasonable amount. prepfully.com/practice-interviews