I went top-down: estimated global smartphone users, split Android vs iOS share, then tried to reason about how many developers would bother publishing to Play vs App Store.
Start by clarifying what 'apps' means (e.g., active, including games, etc.) and then use a structured estimation approach. Break down the problem into addressable market segments, estimate the number of developers and apps per developer, and validate with known benchmarks. Conclude with a range and state assumptions.
Pro tip: Acknowledge that the exact number is not publicly known and changes daily, so focus on demonstrating a logical estimation process rather than the precise figure. Mention that Google Play has millions of apps, and the key is to show structured thinking.
Ask clarifying questions to define 'apps' (e.g., active, including games, etc.) and the time frame (current). This shows attention to detail and ensures alignment.
Decide between top-down (using market data) or bottom-up (estimating developer base and output). For a PM interview, a top-down approach using known figures is often quicker.
Recall or estimate key metrics: number of Android users, percentage who are developers, average apps per developer, and app removal rates. Use round numbers for simplicity.
Multiply factors to get a rough number, then compare with known public estimates (e.g., ~2-3 million apps). Adjust if necessary and present a range.
Conclude with your final estimate, clearly stating assumptions and acknowledging uncertainty. Emphasize the logic over the exact number.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.