PwC Experienced Associate interview questions

After being selected for the interview, did 3 rounds of mainly technical interviews with senior associate, manager, and director. Questions asked by director and manager were pretty difficult related to derivatives.

I applied for the Financial Deals & Analytics team through referral and received an email from the recruiter stating that my resume has been selected for initial technical screen. First round - spoke with a Senior Associate. Only technical questions. Interviewer was polite and friendly. He helped on getting to the answers. Anyone with good preparation can clear this round. Interview Rounds: 1. Technical Screen 2. Interview with Team Manager 3. Interview with Director