How do you deal with clients who delay their payments?

Strange question (for IB, PE) that won't get asked in my opinion (unless I misunderstand the question). IB/PE are people's businesses and generally high trust (given the potential loss of reputation). Bankers do get paid their fees and for PE this is not relevant given there are no "clients". But if it should happen that a client delays its payments to an Investment Bank, let's assume, this should not be the end of the world. Advisors typically get paid at deal closing, so a few months after the actual signing of a deal. As a candidate, emphasize the meaning and true notion of a client service business (which IB is) and that building / maintaining a long-term client relationship matters more than short-term cash flows.

However, a learning that can be taken away from this question is, how to look at this from a corporate finance view. Especially important to understand the impact on the Enterprise Value - Equity Value bridge. Through the "NWC peg" mechanism (Actual closing NWC - Avg. NWC over some time period), a delta in closing NWC over the "normal", i.e. avg. NWC (say over the past 12 months) increases or reduces the Equity Value (cash purchase price) of a company dollar-by-dollar. Important for candidates to understand what this can mean to seller/buyer, e.g. artificial inflation/reduction of NWC. Do not forget that changes in NWC also impact directly your cash balance, and hence, EV / Equity Value as well. Also do not forget, that the seller typically keeps the cash balance on a cash-free, debt-free basis.