I enjoy Hackerrank very much. Although I've been away for awhile from their site. The coding platform was language-choice-flexible and I did a number of challenges in Clojure as a learning experience - very similar to the challenges from your old company, although I only played with round 1 of the security challenge.
I am not a fan of the mathematical challenges on Hackerrank, mainly because I haven't done much interesting math in years and if I get all ambitious on math stuff, I'm going to dive into functional analysis and stats modeling and probably not from a coding viewpoint. Algorithmic challenges are much more engaging to me.
Hackerrank has a very interesting option for hiring companies to sponsor a challenge or set of challenges. Based on what I read here, if I was a hiring company I would be doubling down on this approach (eg coding challenges as a feed for potential hires like you guys were doing as well). Heck, companies would probably pay five to six figures just for a curated list of candidates from these sites, right?
One specific gripe - sometimes I had the vague feeling that the programmatic challenges encourage non-idiomatic language usage. I did a very fun challenge that involved range-minimum-queries there and to ultimately to have runtime under the JVM cutoff and pass all the testcases, I kind of optimized away from the way Clojure normally looks like. I think my point is code that works well for a programming challenge may not look much like code you would want in production.
I can probably spout off more opinions but this is probably already more than you were looking for for someone who didn't use the site for actually finding a job.
They companies have their accounts with Hackerrank and have some bundles for different set of questions (mostly provided by hackerrank itself[1] and could be self created, but mostly they use the questions provided by the hackerrank) - Python, Ruby, Algorithmic, Testing level- and based on the position they'll invite a candidate to try out the questions (via email).
The hackerrank site itself gives a minimal text editor of the language of your choice along with an execution environment. Of the 5 interviews I attended 1 company asked to try the questions while applying itself, 2 companies have sent the invite after a phone level screening and 2 companies invited to their office to attend the same in front of them.
But, some of the questions are more obvious (FizzBuzz, ChessBoard) that often come up in the generic hackerrank for developers section itself..
[[1] - to know the interviewer part I signed up as a Employer which has 14 day trial period and got all their interview questions in stock]
What was the most interesting, involved, or realistic question you dealt with on HackerRank?
If you were a hiring manager, how big a difference would HackerRank make for you? Would you put more weight on the online Q&A, or more weight on in-person interviews?
(If you keep answering me, I'll keep coming up with more questions, because I am not kidding I seriously nerd out on this stuff).
>What was the most interesting, involved, or realistic question you dealt with on HackerRank?
It was a rather most common one(i didn't know it was common at that time) - the infamous fruit basket question and a question to create a word builder from two notepad input to a JSON output to third file and parse the fourth and fifth notepad with the JSON output, something like that... I was/am a beginner programmer, so it was a challenging one but others will find it easy as 1 2 3.
>If you were a hiring manager, how big a difference would HackerRank make for you?
Would be huge.
On my last interview with the company I am joining soon, after all the technical rounds I sat for an one-to-one HR discussion. At that time, it was clear they are going to make me an offer with an CTC for an average professional programmer of my experience (If you'd read my other comments / submissions, All my experience are from SysAdmin job, so I am a fresher for the developer position).
I asked the HR person, "How I am the one sitting here albeit a fresher, rather an experienced dev" his answer, out of 206 applicants only "6" applicants cleared the coding interview and I am one of them. Rest 5 are ruled out on various basis, but the clear point here is, the initial level programming interview (though its more common questions) have subtracted out 98% of the applications which saved huge amount of time for the company. For a company (esp. startups) time is more precious and these kind of initial evaluations surely helps to sweep out the majority of imposters.
>* Would you put more weight on the online Q&A, or more weight on in-person interviews*
In-Person interview any day. Online evaluation can be treated as an filter but can't be a deciding factor.
One problem with online Q&A is its lowest probability to have a fool-proof prevention mechanism. As I previously said, most of the questions are provided by the HackerRank itself, those which can be easily accessed by anyone signing up for a Employer evaluation account and prepare themselves for the interview.
For company created questions, it won't prevent applicants from looking up the answers in Google since most of them are obvious ones. There were some multiple choice questions which if isn't properly crafted will be easy to find answers too.
And most importantly, you can't KNOW a PERSON from these online Q&A. After all we are hiring a Person, not just his knowledge.
>If you keep answering me, I'll keep coming up with more questions, because I am not kidding I seriously nerd out on this stuff
Me too nerd out with these since I have an awesome idea (atleast awesome to me) that fills all these problems with respective to hiring landscape. And you are welcome to come up with questions and I ll try my level best to answer them.
Yes, and I also nerd out on the design of online discussion forums. So watching this discussion trip over a misfeature and nearly fall into the darknet was sad, and sad again.
