There is no magic number. The goal is to show breadth without turning the brainstorm into an unfiltered list. A smaller set of distinct, useful ideas is stronger than many repetitive ones.

Organize ideas into a few logical buckets, give representative examples, then prioritize based on the client objective. If the interviewer asks "what else," add another angle rather than repeating the same category with different wording.

For example, for growth you might cover existing customers, new customers, pricing, and new offerings. After generating, identify which two you would test first and explain why.

Practice stopping once you have covered the main mechanisms and can move into prioritization. The case interview guide is useful for connecting brainstorming to the rest of the case.

I was way too focused on hitting a number like 10 ideas. Four good buckets plus prioritization sounded much better.

ngl the "what else?" follow-up used to make me panic and start repeating myself.

I think the pivot is when you have enough coverage to actually rank the ideas.