Google Photos Hardware Cost Estimation: A Structured Approach

This guide provides a structured framework for estimating the hardware costs per user for Google Photos, a common question in product management interviews at top tech companies like FAANG (Facebook, Amazon, Apple, Netflix, and Google).

Understanding the Framework

The **Cost-Based Estimation Framework** helps break down the problem into manageable components and estimate costs based on known data points.

Step-by-Step Application

1. Identify Costs:

* Storage
* Processing
* Network
* Maintenance

2. Key Drivers:

* Data storage per user
* Number of users
* User behavior patterns
* Redundancy measures

3. Estimate Individual Contributions:

* Average storage per user based on typical photo sizes and usage behavior
* Utilize public data, industry averages, and logical assumptions

4. Total Estimated Cost:

* Aggregate costs associated with each driver

5. Scale:

* Consider economies of scale for a service with millions of users

6. Validate Assumptions:

* Check assumptions against industry benchmarks or logical reasoning

Hypothetical Example

* **Storage:** 2GB per user per month at $0.02/GB/month = $0.04/user/month
* **Processing & Network:** $0.01/user/month
* **Maintenance:** $0.005/user/month
* **Total Hardware Cost:** $0.055/user/month or $0.66/user/year (before scale)
* **Economies of Scale:** 20-30% reduction, leading to $0.46-$0.52/user/year

Effective Communication

* Articulate each step clearly, showing how you arrived at your estimates.
* Be open about uncertainties and explain how you would validate or refine your estimates with more information.
* Stay composed and structured in your response to inspire confidence.

Conclusion

This framework helps you provide a reasoned response, even without specific data points. It demonstrates your analytical skills, product understanding, and ability to handle ambiguity. Practice with various estimation questions to improve your on-the-spot calculations and strategic thinking.