Estimation question

How much space would you need for a photo storage device?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Estimation skill applied to a technical capacity question: converting user behavior into storage volume with clear unit assumptions.

Clarify the scope: storage for one service's users over one year, and confirm whether video is included.
Estimate the user base, for example 1 billion active users.
Estimate photos uploaded per user per day, say 2 to 3, and average file size, roughly 3 to 5 MB.
Multiply users by photos per day by file size by 365 to get annual raw storage.
Adjust for compression and replication factors typical of cloud storage before giving a final number.

Separates raw storage from replicated storage, since production systems typically keep 2 to 3 copies for durability.
Converts the result into a familiar unit, for example several exabytes per year, so the number is easy to sanity check.
Notes that thumbnails and multiple resolutions add meaningfully to total footprint.

Forgetting replication and backup copies, which understates real storage needs by 2 to 3x.
Picking an unrealistic file size assumption without stating it as an assumption.

Chapters of the AI PM course that teach what this question tests.