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I am asked this question many times in the interviews.

What was your most challenging project -- and why?

I get confused about which project to tell them and why some project would look challenging or non-challenging. What are they looking for in the answer? Any software is a challenge before it gets started and it becomes a normal software engineering task after it has finished. All softwares I made were challenging until they got finished. Do I misunderstood the word "challenge"? What's wrong in my thinking?

What's an appropriate and constructive way to approach this question?


migration rejected from Jan 23 '14 at 14:12

This question came from our site for professional and enthusiast programmers. Votes, comments, and answers are locked due to the question being closed here, but it may be eligible for editing and reopening on the site where it originated.

closed as primarily opinion-based by Jim G., gnat, GlenH7, MichaelT, World Engineer Jan 23 '14 at 14:12

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.If this question can be reworded to fit the rules in the help center, please edit the question.

this is the wrong place for this question. – dqhendricks Jan 14 '11 at 0:44
FizzBuzz was by far my hardest. – Job Jan 14 '11 at 2:00
ironic that the community doesn't think this is constructive, but the site's twitter feed think it's "interesting":!/StackProgrammer/status/25732730184540160 – matt b Jan 14 '11 at 2:57
@matt I think it's constructive if it focuses on approaches to answering this question; if it is soliciting individual answers to the actual question, it is not. – Jeff Atwood Jan 14 '11 at 7:08
I think that they are looking for passion: – ruslik Jan 14 '11 at 7:37

Yes, all projects are challenging, but you likely remember one or two projects that was like ten times more challenging than usual:

  • non-functional requirements were not set initially had to be identified by tedious trial and error and also
  • designing seemed mission impossible and also
  • thorough testing requied significant effort and also
  • deployment package preparation seemed mission impossible

... so that it looked like everything was against you yet you shipped a good solution in reasonable time. Then you should surely name that project - your description of the major problems and their solutions will show how tough you are.


This question could be an attempt to see how will you identify weaknesses that you had and what did you do to overcome them. While figuring something out is how I see a challenge, this question is aimed a bit at seeing where did I grow the most from being pushed to my limit. Here would be the main points of how I'd answer the question:

  • Background of where I was at the start of this project.
  • General nature of the project.
  • Results from the project, so that this is concluding the basics of the story.
  • Explain where I had problems and difficulties in getting this done, what did I do to conquer them and what other changes I'd make if I was in a similar situation now.

This question has lots of possible ways to sabotage oneself in answering as it can be rather easy to bad mouth a former employer or complain on something that if you get into too much of a rant, then you fell into the trap. The other point is being able to summarize something so that you aren't long-winded but yet give enough detail so that the interviewer can follow the story and understand what you did, how you did some of it and why it was so hard. Thus the question is asking you to walk a fine line and see how well you walk on that tight rope.


A new trend/fad/fashion in interviewing is called a "competency based interview". In this fashion, the interviewer is supposed to come up with a list of key job skills and then base some open-ended questions around those skills. Sample questions based on key skills.

It is my belief that more and more people trying to hire developers will turn to these sorts of questions and get away from the stupid trivia questions we've seen in the past (such as "what is the third parameter of the print function"). While those trivia questions are reasonable at determining if you have had some exposure to a language/framework, they aren't good at determining if you "fit" in with a team, or if you are a "good" (for any sort of value of "good") developer.

"What was your most challenging project? and why?"

This question is trying to determine your problem solving skills, with a side of determining what you consider to be challenging. In a high pressure environment, what you consider "challenging" might be something that they do every day.


The best way to answer is truthfully. There are many factors that make projects challenging

  • Technical Difficulty
  • Personality conflicts
  • Insane deadlines
  • Boring, outdated platform/framework
  • Cutting edge, untested, unstable platform/framework
  • Personal issues at home

Pick something that was a challenge to you, and discuss how you overcame those challenges or even how you succumbed to the pressures but learned and grew from the experience. There's a difference between not succeeding and failing. You only fail when you don't learn a lesson from non-success.

And being able to admit failure is more impressive than crowing about success through over-whelming odds. – Michael Brown Jan 14 '11 at 8:42
What's even better is saying "and from that failure I took steps X, Y, and Z to make sure it has never happened since. Because of that, in my last project I was able to do A so well that..." Showing how you concretely learn from your mistakes is a huge plus. – justkt Jan 14 '11 at 16:12
I definitely would not bring up personally issues at home. Even if that's given you trouble in the past, its not something you want to mention. – William Morrison Dec 22 '14 at 18:52

There is no deeper sense in this question. It is a question phrased in a way such that you can freely, creatively talk about something that you deem

  1. Interesting
  2. Challenging
  3. Worth telling... and...
  4. Makes you proud a little bit

Imagine them asking about your most boring repetitive task? Who'd care? No one. But a story about the most challenging project in your career really tells a lot about you as a person and how you deal with things. So you can even tell them about taking your grandma to hospital or marrying your wife or constructing that remote-controlled airplane or whatever, as long as you think you can meet points 1-4.


This is an open-ended question and the right answer is how you answer it, not really the content. You are trying to convince the interviewer that you are a good investment, will work hard, you're not a risk, you get along well with others and you can come to an agreement on the money. Whatever you answer, make sure it is wrapped around all but the last of the conditions but the last one as that will come at the end of the interview.

A good answer would be that your most challenging project was something that you did that had a big impact on the customer and had an aggressive set of needs attached (low coding time, high skill needed, very fast program requirements, very low cost to build, etc.) combined with a feeling that you had really enjoyed the process. You seek out challenges and are the kind of worker who isn't afraid to take on the most complicated assignments. I would then add to that how you feel about challenging projects as something that allows you to connect to a higher purpose in your career. There will always be assignments that are operational or routine, but the challenging tasks completed successfully are what ultimately make you, your teammates and your employer better off.

Since the hiring manager can assume that you can do the routine tasks, the question about the challenging projects will reveal your level of skill, effort to complete tasks, teamwork, enthusiasm and determination. No answer is perfect or will work for everyone, but as you talk to the interviewer remember that people hire people, not companies hire people. The interviewer is looking to find out if you resonate with what he or she wants. Find out early what they are looking for in the ideal candidate and what the culture is at the company.

If the boss has a work culture of heads-forward, trial by fire and work 50 hour weeks only to go home and work more, then your answer to "What was your most challenging project -- and why?" will need to reflect that you would fit in there. When all else fails, respond in answers that fit the culture and show you focus on fast, accurate and educated results.


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