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Google·Product Manager·Onsite - Product Sense / Strategy·Intermediate

Intermediate
May 2026

Summary

Google PM interview with a classic estimation question about Uber's driver supply in the Bay Area. Short on details but the question itself is a solid case study in market sizing.

Questions Asked (1)

Q1

How many drivers does Uber need to serve the San Francisco Bay Area?

Product Analytics & MetricsProduct Sense & Ideation
Author's notes

Classic supply-side estimation.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the goal: estimate the number of drivers needed to meet demand at a given time, not total registered drivers. Use a demand-driven approach: estimate peak demand (rides per hour) and divide by the average rides a driver can complete per hour, adjusting for utilization and geographic distribution.

Pro tip: Acknowledge that this is a supply-demand matching problem and that the answer depends on assumptions like time of day and desired wait times; state that you'd validate with real data and iterate.

1. Clarify the objective and scope

Ask whether we're estimating drivers needed for peak demand, average demand, or total registered drivers. Clarify if we're focusing on a specific time (e.g., rush hour) or overall coverage.

2. Estimate demand

Calculate the number of ride requests per hour during peak times by estimating the Bay Area population, adoption rate of ride-hailing, and average rides per user per hour.

3. Estimate driver supply capacity

Determine how many rides a single driver can complete per hour, considering average trip duration, pickup time, and idle time between rides.

4. Calculate required drivers

Divide total demand (rides per hour) by the number of rides one driver can serve per hour to get the number of active drivers needed. Adjust for utilization rate (e.g., if drivers are only 70% utilized, divide by 0.7).

5. Sanity check and iterate

Validate the number against known metrics (e.g., Uber's reported driver numbers in similar markets) and consider factors like part-time drivers, shift patterns, and geographic spread.

Key Points to Mention

  • Distinguish between peak demand and average demand; drivers needed for peak may be higher.
  • Consider driver utilization rate: not all drivers are active or completing rides at all times.
  • Account for geographic distribution: drivers must be positioned where demand is.
  • Use a top-down approach: start with population, then narrow down to ride-hailing users.
  • Mention that the estimate should be validated with real data and adjusted for seasonality, events, etc.
  • Acknowledge that Uber uses dynamic pricing and incentives to balance supply and demand.

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.