I started with storage since that's the obvious one, but then kind of froze trying to figure out whether to account for compression, deduplication, tiered storage across hot and cold buckets.
Break down the cost into major components: storage, compute, network, and operations, then estimate each using reasonable assumptions about user scale and usage patterns. Structure your answer by first stating assumptions, then calculating costs, and finally discussing key drivers and trade-offs. Emphasize that this is a product management estimation, focusing on order of magnitude and strategic implications.
Pro tip: Anchor your estimate with known public data (e.g., Google Photos has over 1 billion users, and Google's total cloud storage is exabytes) and use round numbers to simplify calculations. Show that you understand the difference between marginal cost and fully loaded cost, and highlight how product decisions (e.g., compression, tiered storage) impact the bottom line.
Define what 'managing Google Photos' includes (storage, serving, processing, etc.) and state key assumptions like number of users, average photos per user, and storage per photo.
Calculate total data stored by multiplying users, average photos, and average file size. Then apply a cost per GB per month for cloud storage (e.g., Google Cloud Storage rates) to get annual storage cost.
Consider costs for image processing (uploads, transcoding, ML for search), serving images (CDN egress), and ongoing operations. Estimate based on usage patterns and cloud pricing.
Add up storage, compute, network, and operational costs to get a total annual cost. Sanity-check against Google's overall cloud spending or revenue to ensure plausibility.
Highlight factors that most impact cost (e.g., user growth, compression algorithms, storage tiering) and how product decisions can optimize costs while maintaining user experience.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.