How Would You Move Mount Fuji? Microsoft's Cult of the Puzzle

1. Microsoft's Puzzle Interview: A Quest for Creative Thinkers

Microsoft’s interview process is a notoriously grueling sequence of brain-busting questions that separate the most creative thinkers from the merely brilliant.

Beyond Skills: Microsoft's interview process, renowned for its difficulty, aims to identify candidates who possess original and creative thinking abilities, rather than just assessing their existing skills or knowledge. This approach reflects the company's belief that in the fast-paced tech industry, adaptability and problem-solving skills are more valuable than specific expertise. The goal is to find individuals who can question assumptions, approach problems from novel perspectives, and thrive in an environment of constant change.

The Impossible Question: A key element of the Microsoft interview is the "impossible question," a riddle or hypothetical scenario that has no definitive answer. These questions, such as "How many piano tuners are there in the world?" or "How long would it take to move Mount Fuji?", are not meant to test factual knowledge but rather to gauge a candidate's ability to think on their feet, structure their thoughts, and articulate a logical approach to an ambiguous problem. Interviewers often don't know the "correct" answer themselves, emphasizing the process over the outcome.

A Broader Trend: The puzzle-laden job interview, once unique to tech companies, has now infiltrated various sectors, including finance, consulting, and even the armed forces. This trend reflects a broader shift towards valuing adaptability and problem-solving skills in an increasingly uncertain and competitive global marketplace. Companies are seeking employees who can think critically, question assumptions, and innovate in the face of constant change.

2. The Historical Roots: From IQ Tests to Silicon Valley

No one has done more to define intelligence and make mental assessments a part of hiring than Stanford psychologist Lewis M. Terman (1877–1956).

Lewis Terman's Legacy: The concept of intelligence testing in hiring can be traced back to Lewis Terman, a Stanford psychologist who popularized the IQ test and advocated for its widespread use in schools and workplaces. Terman believed that intelligence, defined as the ability to reason abstractly, could be measured and used to match individuals to suitable jobs, creating an ideal meritocracy. His work laid the foundation for the use of standardized tests in employment decisions.

Shockley's Semiconductor and the Puzzle Interview: William Shockley, a pioneer in transistor technology and founder of Shockley Semiconductor Laboratory, incorporated intelligence tests and logic puzzles into his hiring process in the 1950s. He sought to recruit the most talented engineers and scientists, believing that problem-solving ability was crucial for success in the rapidly evolving field of semiconductors. This early adoption of puzzle-based interviews in Silicon Valley contributed to their later popularity in the tech industry.

The IQ Disenchantment: Despite the initial enthusiasm for intelligence testing, concerns about cultural bias and discriminatory practices led to a decline in their use in hiring. However, the underlying desire to assess cognitive abilities persisted, leading to the adoption of puzzle interviews as a seemingly more egalitarian and relevant alternative. These interviews aimed to measure "bandwidth," inventiveness, and creative problem-solving skills, rather than relying on traditional measures of intelligence.

3. Bill Gates's Puzzle Obsession: Shaping Microsoft's Culture

The family of Seattle attorney William Gates II was a big believer in organized fun.

Games and Competition: Bill Gates's upbringing fostered a love for games, puzzles, and intellectual competition. His family emphasized organized fun, with regular tournaments of bridge, Password, and trivia games. This competitive spirit carried over into his leadership at Microsoft, where a culture of one-upmanship and a relentless pursuit of winning permeated the company's ethos.

Math Camp Mentality: Microsoft's internal culture, often described as "math camp," valued intelligence, logic, and problem-solving abilities above all else. Employees were expected to be highly competitive, constantly striving to outsmart their rivals and push the boundaries of innovation. This environment fostered a unique blend of intellectual rigor and playful competition, with practical jokes and whimsical games serving as both a respite from and a concentrated form of the company's pressures.

The Innovator's Dilemma: Microsoft's leadership, including Gates, has long been preoccupied with the fear of becoming complacent and being overtaken by disruptive technologies. This paranoia, fueled by Clayton Christensen's "The Innovator's Dilemma," has driven the company to prioritize innovation and seek out individuals who can challenge assumptions, adapt to change, and solve complex problems creatively. The puzzle interview became a key tool in this quest for talent.

4. Decoding the Puzzles: Types and Examples

Microsoft’s interview questions are intended to be secret.

Beyond Traditional Questions: Microsoft's interviews go beyond traditional and behavioral questions, incorporating brainteasers, trick questions, and open-ended hypothetical scenarios to assess a candidate's problem-solving abilities and creative thinking. These questions are designed to be challenging and ambiguous, requiring candidates to think on their feet and articulate their reasoning process. The goal is to evaluate how candidates approach complex problems, not just whether they can arrive at the "correct" answer.

Logic Puzzles: A significant portion of Microsoft's interview questions consists of logic puzzles, recreational problems that require deductive reasoning and analytical skills. Examples include:

• "You have eight billiard balls. One of them is 'defective,' meaning that it weighs more than the others. How do you tell, using a balance, which ball is defective in two weighings?"
• "You have a 3-quart bucket, a 5-quart bucket, and an infinite supply of water. How can you measure out exactly 4 quarts?"

Impossible Questions: Another type of question involves estimating quantities or solving hypothetical problems that seem impossible to answer with certainty. Examples include:

• "How many piano tuners are there in the world?"
• "How long would it take to move Mount Fuji?"

Design Questions: These questions ask candidates to design a product or system, such as a microwave oven controlled by a computer or a spice rack for a blind person. The goal is to assess the candidate's ability to think creatively, consider user needs, and make trade-offs.

5. The Cognitive Science of Puzzles: Embracing Cluelessness

To understand that cleverness can lead to stupidity is to be close to the ways of Heaven.

Solution Spaces and Clueless Plateaus: Cognitive scientists like Herbert Simon and David Perkins have studied problem-solving processes, highlighting the importance of searching a "solution space" and navigating "clueless plateaus." Simon believed that problem-solving involved a rational search for solutions, while Perkins emphasized the role of intuition and persistence in overcoming uncertainty. These perspectives offer insights into the cognitive skills that puzzle interviews aim to assess.

Uncertainty and Disjunction: Many puzzles exploit the human tendency to avoid uncertainty and disjunction, the either-or situation where exactly one of two or more mutually exclusive possibilities is true. People often struggle to reason from uncertain premises, preferring to focus on known information. Overcoming this cognitive bias is crucial for solving many logic puzzles and real-world problems.

The Framing Problem: The "framing problem" in AI refers to the difficulty of knowing what is relevant to a given situation and what can be safely ignored. Similarly, many puzzles are designed to exploit faulty assumptions and require solvers to reframe the problem by questioning their initial premises. This ability to step back, analyze assumptions, and consider alternative perspectives is a key skill for innovators and problem-solvers.

6. Wall Street's Adoption: Stress and the Absurdist Interview

“Let’s play a game of Russian roulette,” begins one interview stunt that is going the rounds at Wall Street investment banks.

From Tech to Finance: The puzzle interview, initially associated with tech companies like Microsoft, has spread to other industries, including Wall Street. Investment banks and consulting firms have adopted these techniques to assess candidates' problem-solving abilities, stress management skills, and ability to think on their feet. This adoption reflects the increasing complexity and fast-paced nature of the financial industry.

The Stress Interview: Wall Street firms are known for their "stress interviews," which aim to put candidates under pressure to see how they react. These interviews may involve silence, personal attacks, or absurd scenarios, such as asking the candidate to open a window in a skyscraper office where the windows don't open. The goal is to assess how candidates perform under pressure and whether they can maintain composure in challenging situations.

The Absurdist Interview: Some companies have taken the puzzle interview to extremes, incorporating bizarre tasks and questions that seem to have little relevance to the job. These "absurdist interviews" may involve building something out of Lego blocks or defining the color green. While these techniques may be intended to assess creativity and problem-solving skills, they often come across as arbitrary and demeaning.

7. Navigating the Labyrinth: Strategies for Success

If this appears a paradox, it is only because these interviews have been touted as being difficult or impossible to “prepare” for.

Know the Game: While puzzle interviews may seem unpredictable, there are certain patterns and strategies that can help candidates improve their performance. Understanding the types of questions, the underlying cognitive tricks, and the unspoken expectations of the interview can give candidates a significant advantage. Preparation is key to success.

Key Strategies:

• Determine the expected answer type (monologue or dialogue)
• Assume the first thought is wrong
• Avoid calculus and overcomplicating
• Recognize "perfectly logical beings"
• List assumptions and challenge them
• Lay out possible scenarios
• Give original answers

The Challenge: Be prepared for the "Challenge," a technique where the interviewer argues with a candidate even when they are correct. The goal is to assess the candidate's ability to defend their position, persuade others, and remain confident in their knowledge.

8. Reimagining the Interview: A Proposal for Innovation-Driven Companies

The strongest argument for puzzle interviews is that everything else is worse.

Focus on Negative Screening: Puzzle interviews are most effective as a negative screen, identifying candidates who lack essential problem-solving skills or the ability to think critically. They should not be used as a primary means of identifying "geniuses" or making hiring decisions based solely on puzzle-solving ability. The goal is to avoid bad hires, not necessarily to find the "perfect" candidate.

Fairness and Transparency: Interviewers have a responsibility to ensure that the interview process is fair and transparent. This involves explaining the purpose of the questions, avoiding biased or discriminatory practices, and providing candidates with clear expectations. The goal is to create a level playing field where all candidates have an opportunity to demonstrate their abilities.

Beyond Puzzles: While puzzles can be a useful tool, they should not be the sole focus of the interview. It is important to assess candidates' experience, skills, and personality through a variety of methods, including traditional and behavioral questions. The goal is to gain a holistic understanding of the candidate's potential and fit within the company culture.

Last updated: February 15, 2025