I'm a bit of an outlier here because I'm a PM-to-SWE pivot and I tend to actually pay attention to the behavioral rounds most engineers dismiss. Went through MS behavioral earlier this month for a senior SWE role.
They do not use a branded framework like Amazon's leadership principles or Goldman's published competencies. Instead the questions feel more... traditional competency-based. STAR format is fine but they don't prompt you to use it.
Questions I got (these are close to verbatim): "Tell me about a time you had to make a technical decision with incomplete information. What did you do and what happened?" "Describe a situation where you disagreed with your team's technical direction. How did you handle it?" "Walk me through a time a project you owned went sideways. What was your role in it?" "How have you mentored junior engineers? Can you give a specific example?"
For a senior IC role they spent a lot of time on the mentorship question. I think at VP-equivalent they really want to see that you can develop people, not just ship code.
The culture at Morgan Stanley tech is more formal than FAANG and more politically navigable than pure bulge-bracket finance. A few things that seemed to land well in my answers: talking about documentation, cross-team communication, and being thoughtful about risk before shipping. That last one especially. You can basically work "we did a thorough risk review before releasing to production" into any story and they visibly appreciate it.
Thing that doesn't land: FAANG-style move-fast framing. Don't say "we shipped fast and iterated." Say "we validated the approach with a limited rollout before the full release." Same thing, different framing, very different reception.
Total behavioral time was about 30 minutes across two interviewers. One was my future potential manager, one was a peer from another team. The peer was less structured with follow-ups.