Google Interview Guide

Preparing for my Google interview took almost 40 hours. I never prepared so much in my life for one interview. I reviewed case studies, my own STAR stories, did practice interviews, and tons of research. It all comes down to four critical areas:

  1. General Cognitive Ability (GCA)
  2. Leadership
  3. Role-related Knowledge
  4. Googleyness

For more details, see the official Google Interview page and How we hire page.


General Cognitive Ability (GCA)

The purpose of this section is to understand to your problem solving skills.

Can you take a small set of data, ask questions, make assumptions to come to a conclusion?

An example would be like the following: How much money does Google make in a year out of Gmail in the US?

An extreme example would be below:

How many iPhones are sold in the US each year?

  • Summarize
  • Understand the objective
  • Ask clarifying questions
  • Share problem solving roadmap
  • Assumptions
    • 300 Million people in US
    • 90% of people have a cell phone
    • Cell phone users are locked into two year contracts
    • Each person only buys 1 phone
    • Smartphones are 40% of new cell phone sales
    • Apple iPhone has 35% market share of smartphone market
  • Calculations
    • Number of people looking to buy a phone each year:
    • (300 Million people in US) x (90% people have a cell phone) x (50% will be buying a new phone this year) = 135 Million
    • Number of people that will buy iPhones each year:
    • (135 Million people will be buying a new phone this year) x (40% will get a smartphone) x (25% of smartphone buyers will buy an iPhone) = 13.5 Million

Finally, another helpful resource would be consulting firms case study interview prep guides.

  • What are your communication and decision making skills to mobilize others?
  • Can you influence without direct authority?
  • Give examples of:
    • Motivating
    • Influencing
    • Mentoring
    • Impacting
Role-related Knowledge
  • Show your strengths through experience
  • Show your ability to grow
  • Go deep with examples
  • Speak to resources used
  • Results don’t always have to be quantitative

How do you work on a team?

How do you navigate ambiguity?

The book ‘How Google Works’ defines it as:

  • Thrive in ambiguity
  • Value feedback
  • Challenge the status quo
  • Put the user first
  • Do the right thing
  • Care about the team

General Tips

  • Take time in the interview to listen to the questions – write each one down and take a moment to draft out your response vs jumping right in 
  • Don’t feel intimidated by questions with no data.  Ask for info and if none, make assumptions and provide insight into why you made them 
  • Be careful not to only present one note responses.  Think of a variety of ways to answer a question/provide a solution 
  • Take a second to think about why you are being asked that question in the first place.  Once you know why, focus on making sure your answer addresses the skill that question in digging for
  • Understand the manager’s pain points
  • Have an emotional connection to the products
  • Have a one sentence pitch about yourself
  • Be memorable with your stories
  • Break down the job