FP&A interviews mix three things: variance questions ("costs came in 12 over, is that good?"), forecasting questions ("we're six months in, what's the full-year number?") and unit economics ("how long does a customer take to pay back what we spent to win them?").
Each question gives the facts on the sheet. Work it out in your head or on paper, then type the number. Percentages can be typed as 15% or 0.15. Answers within the tolerance count.
For variances in this set, think in profit terms: a cost that comes in over budget hurts profit, so its effect is negative. For unit economics:
- CAC payback (months) = CAC / (monthly revenue per customer x gross margin)
- LTV = monthly revenue per customer x gross margin / monthly churn
The hard questions combine two steps. Write the first result down before you start the second.