Blackcap Blog

Published at 12:02 on 31 May 2024

Foreword

I have thought of writing this article more than once before. I just got assigned yet another HackerRank test as part of an interview process. Sometimes, I have blown such things off entirely. Sometimes, I attempt to do my best on answering them.

This time, I plan to do something different. I will have a link here in my response to the problem; if you are reading this as a result of following that link, then here is why I responded the way I did.

Introduction

HackerRank sucks for two main reasons:

1. The general irrelevance of undergraduate computer science exercises to real-world programming, and
2. The artificiality of HackerRank’s time constraints.

Irrelevance of Problems

In my experience, HackerRank’s exercises tend to be thinly-disguised rehashings of undergraduate computer science homework assignments. Such assignments tend to be heavily based on coding implementations of basic data structures, often trees of various sorts, that have very limited real-world relevance to solving problems on the job. I have written on this here before. It’s really not a surprise, given how the usage of such problems is basically mandated by the general nature of the constraints of the HackerRank platform.

Effectively, such tests screen for either recency of undergraduate coursework (and thus lack of practical, on-the-job experience), or willingness to spend time brushing up on a skill set whose real-world utility is extremely limited (and thus for unquestioning submission to authority and willingness to obey pointless rules). The first is diametrically opposed to the goal of filling a senior-level position, and the second is diametrically opposed to the sort of environment that I personally thrive in.

Artificiality of Time Constraints

Real-world programming tasks generally do not pop unexpectedly out of nowhere, with no advance warning. They are usually foreseeable as part of the natural trends of evolution of software systems and the organizations they support. As such, the prudent developer has usually already spent some time thinking about such issues. Sometimes, of course, they do pop up unannounced (long-latent bugs sometimes manifest, and sometimes have severe impact). Even then, they don’t come with a count-down timer and a hard artificial deadline. It is possible to take a walk (I get some of my best ideas outdoors) or to bounce ideas off colleagues.

With HackerRank, there is no such subtlety. The clock is ticking, the artificial deadline is rapidly approaching, and it will be enforced without mercy. (Sometimes you even get a so-called proctored test, in which you must enable a spy camera. Leaving the room is considered cheating. Lucky you.) You will solve the problem in one sitting, and you will do it now. And the problem has limited real-world relevance at best.

Conclusion

Maybe I will submit an actual solution, and maybe I will not. It will depend on the exercise and how I feel about it at the time I submit my response. At any rate, the link here will be the most important part of that response.

Really, there is not much more to say, so it is time to wrap this up. HackerRank sucks, and now you know why.