Introduction
Securing a product management role in a FAANG company necessitates a sharp analytical mind and the ability to estimate and make decisions with incomplete data. A typical interview question to test this skill might be: How many messages in Gmail per second? This blog post aims to guide aspiring product managers on how to tackle such estimation questions using the frameworks and strategies from ‘Decode and Conquer: Answers to Product Management Interviews.’
Detailed Guide on Framework Application
Picking a Framework
The Fermi Estimation technique is appropriate for answering questions involving large-scale estimations like this one. This method breaks down complex problems into smaller, more manageable estimates.
Step-by-Step Guide
Applying the Fermi Estimation involves the following steps:
- Define the Problem: State clearly what you are trying to estimate—in this case, Gmail’s messaging traffic per second.
- Breakdown the Problem: Consider factors such as the number of Gmail users, average email usage per user, peak and off-peak hours, and types of users (personal vs. business).
- Make Educated Guesses: Use publicly available data or logical assumptions to estimate each component. For example, consider the total number of internet users and the market share of Gmail to estimate its user base.
- Perform Calculations: Multiply your estimates to get an approximation of the total number of messages per second.
- Refine and Adjust: Revisit your assumptions and adjust the estimates based on logical reasoning or additional data you may have recalled.
- Present Your Answer: Finally, synthesize your calculations and reasoning to present a coherent estimate to the interviewer.
Hypothetical Example
Let’s say we start by estimating that Gmail has 1.5 billion users. Assuming on average, a user sends 5 emails per day, we would get around 7.5 billion emails daily. Now considering emails are not sent uniformly throughout the day and spiking during business hours, let’s estimate 20% are sent during the busiest hour. That leads to 1.5 billion emails at peak hour. Breaking it down further, this gives us roughly 416,667 emails per second during peak time.
Fact Checks
It’s essential not to get caught up on accuracy but to demonstrate logical thinking and comfort with approximations. Use common sense and broadly accepted facts to support your estimates.
Communication Tips
When communicating your estimate, walk the interviewer through your thought process. Clearly explain each assumption and calculation. Display confidence in your reasoning while acknowledging the rough nature of the estimate.
Conclusion
Estimation questions like Gmail’s messaging traffic per second test an interviewee’s ability to think quantitatively and deal with ambiguity. By employing the Fermi Estimation technique and demonstrating a structured thought process, candidates can deliver impressive and plausible estimates. Practice this approach with various scenarios to enhance your analytical skills and intuition, which are crucial for success in product management interviews, especially within FAANG companies.