I got all my tech interview questions right but didn't get a job

What you'll learn

Importance of Thought Process in Interviews

Accounting for Solution Scale

Communicating Technical Ideas Effectively

Seeking Interview Feedback

Here is the scenario, You go to a tech company for an interview and get every single one of their questions correct.  Yet you do not land the job.  Why not?

Well the short answer is that getting the correct answer to riddles, math algorithms or other questions may have a small influence on an interviewers overall decision making process.  Most interviewers consider those type of questions more of bare minimum.  Meaning - if you are applying to be an engineer then you should be able to logically figure out practically any problem I give you - however simply providing the right answer does not mean you are the right fit for the job.

Maybe it was your thought process?

Whenever I ask a difficult question to a candidate, I often care more about the thought process involved in arriving at a conclusion, rather then a black and white - did the candidate get the right answer.  Good software engineers understand that there are dozens of ways to solve the same problem.  A rockstar engineer evaluates his thought processes to account for the following considerations:

• WIll this solution introduce latency into the system.  Is there another, more efficient approach that should be used instead.
• Will this solution be easily understood by others.  Sometimes simplicity is better over elegance in team environments.
• Will this solution provide a way to monitor, control, debug, etc.  Creating the feature is only part of it, how does one maintain it.
• Will this solution scale and where will the bottlenecks be.  Solutions that are flexible and logically separated scale more efficiently.

Was scale accounted for?

When scale is not involved a lot of solutions will work just fine.  Once scale gets involved a lot of solutions have to be thrown out the door.  This is one of the most common issues with candidates who "got the correct answer but didn't pass".  Their solution might truly work just fine in a synchronous flow for 1 request yet brake down when scale is added.

Here is an example conversation that sometimes happens during an interview:

• Interviewer:  How would you program a routine to do XYZ?
• Candidate:  I would program it by doing [foo], then by doing [bar]
• Interviewer:  Ok.  That makes sense and I see how that would work.  How will that scale when 1 million users a day access it?
• Candidate:  it would probably suffer performance issues.

Do you see the problem with this scenario?  The candidate just simply gave a quick answer without much thought into how it would break down at scale.

Can you communicate your ideas?

A candidate interviewing with me must also be able to provide a logical discussion around the solution that addresses the points above.  Getting the correct answer is only a small portion of.  In other words - you have to understand and demonstrate why your solution is the best out of 100 other possibilities.

The reason for this is simple.  During your day to day tasks you will need to interface with designers, product managers and slew of other roles that are not as technical as you are.  If you are unable to communicate with them then your value with the company is diminished.

Should you ask for Feedback?

From a general standpoint, the recruiter working with you to arrange the interviews is generally not the same person that is performing the final evaluation.  They still will pass judgement on you - but they are often not the subject matter experts that will validate your skills.

For this reason you can often ask questions more around feedback and insight.  Be sincere with the recruiter and ask for feedback about your skills being a match for the job.  be understanding that the recruiter will not be able to share exact details but can generally give general feedback.  This may include a lack of skills in a certain area, not enough experience in a certain role, etc.  Detailed feedback is often not provided so that a heated debate style exchange is avoided.

It also possible that no feedback will be provided.  While disappointing, it does happen.  Understand that this is natural and do not take it personally.  In some cases it is very difficult for recruiters to follow up will all candidates and provide valuable feedback on why a potential opportunity was passed upon.