Reverse Engineering Engineering Interviewing: How to Be a Great Interviewer

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Conducting Great Engineering Interviews

Reverse Engineering Interviews to Reduce False Negatives

Gayle Laakmann McDowell

July 2014


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Gayle Laakmann McDowell

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Author Interview Coach Interview Consulting

(CS) (MBA)



The Problem(s)

1. Candidates suck at interviewing.2. You want to hire good employees, not good

candidates.3. Shortage of great engineers.

Be a better interviewer.Be a better recruiter.

By counteracting…



What I Coach

Download at: CrackingTheCodingInterview.com



Traditional Dev Questions

Startups “Elite” Other

Behavioral/Experience

Knowledge-Based

System Design/Architecture

Algorithms/Problem-Solving✔

?

✔

?✔

?

?

Disclaimer: So. Many. Exceptions.



How can you help candidates be their best?

Behavioral Problem Solving



Behavioral Questions: Mistakes

• Underplaying individual contributions• Using “we” not “I”• Not elaborating on actions

• Don’t assume• Probe for details



Generalist vs. Specialist

• Generalist (algorithms/problem-solving):– Hires smart, adaptable people if done well– BUT necessitates “onboarding”

• Specialists (knowledge & experience):– Hires immediately useful people– BUT is the knowledge actually difficult to acquire?



Generalist vs. SpecialistHires smart,

adaptable people

BUT requires “onboarding”

+Doing it right

Hires immediately useful people

BUT is it really specialist

knowledge?



Generalist(ish) Hiring

So you’ve gone generalist(ish)…



Algorithm Questions

“Problem-Solving Questions”

= Solving a problem you have NOT seen before.



Problem-Solving Questions

few false positives(only good people pass)

but…

lots of false negatives(many good people fail)



Why Problem-Solving Questions Work

• Smart people do good work.• Adaptable as company changes

So why so many false negatives?



Why Smart People Fail

1. Knowledge gaps2. Intimidation3. Arbitrary questions4. Not knowing how to be good

These are [partially] solvable problems.



This matters!

• Goal: good employees, not good candidates.• Do you want to eliminate…–Everyone who doesn’t know ___?–People who are insecure?–People who are bad at interviewing?–People at random?



1: Knowledge Gaps (Why?)

• Not knowing fundamental CS knowledge– Especially older people!

• Obscure CS knowledge being tested– Making questions “hard” via knowledge.



2: Intimidation (Why?)

• Low self-confidence.• Scary questions.• Candidates misunderstanding interview goals.• Interviewers being [unintentionally] rude.



3: Arbitrary Questions (Why?)

• Well-known questions.• Easy questions.• “A-Ha” moments & singular hurdles.



4: Not Knowing How To Be Good

• Didn’t use an example.• Tried to rush the process.• Didn’t walk through problem.



Design Around This

1. Decide what you value.2. Ask the right questions.3. Give candidates tools to prepare.4. Train your interviewers.



1. Decide What You Value

• Is problem-solving skills a top priority?• What sorts of specialist skills do you need?• Are fundamentals of CS sufficient?



2. Ask the Right Questions

• Right topics:– Avoid scary topics.– Require only basic CS knowledge.

• Right difficulty:– Medium & hard problems. – Avoid common problems.

• Logical path with multiple insights.



3. Give Candidates Tools to Prepare

• Tell them:– What to expect.– How they’ll be evaluated.– Struggling is normal.

• Links to preparation resources.



4. Train Your Interviewers

• How to design good questions.• Be extra nice to candidates.• Coach candidates to be great



4b. Coach Candidates To Be Great

• Encourage the right example.• Remind them of details.• Don’t let them dive into code.• Encourage shifting gears.• POSITIVITY & SENSITIVITY

A good coach can make a HUGE difference!



Need The Right Infrastructure

• Interview training• List of good & bad questions -- and why• Standard resource sheets for candidates• Feedback from candidates• Assigned roles• Continuous evaluation & shadowing



It sh

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Recruiting & HR

Reverse Engineering Engineering Interviewing: How to Be a Great Interviewer