[dundercoder]

I had never even heard of HackerRank before applying at a few places. I was supposed to write a binary search tree algorithm without using anything except the language docs. I rarely write anything new without a quick search, it wastes valuable time reinventing the wheel.

[ashark]

I find I often forget basic language syntax when I don't have adjoining lines to crib from, say, when white boarding. And that's with languages I'm actively working in—I'm hopeless in anything I haven't used in a couple months, even if I wrote in it daily for the five years before that. I'll flat out forget which language features it supports, or how to address them.

[Pokepokalypse]

Same. 25 years experience. (especially now that I have about a dozen obsolete languages under my belt). This is fine in daily practice, and does not interfere with productivity. But getting through that hiring filter; devastating.

[ashark]

I hope that this is because I have, over the years, become like Liezi's good judge of horses[1], but fear it's just that I have a bad memory for programming language details. Probably it's a bit of both.

[1] https://www.reddit.com/r/taoism/comments/38h66v/liezi_book_8...

[corporateslave3]

I had this as well, an off by one error on a binary search resulted in a rejection...

[toomanybeersies]

I had a really good tech interview a while back, where I had to reverse a string in place, and then reverse only the words in a string in place (so "this is a test" => "siht si a tset")

Anyway, I had a couple of off by errors. The interviewer asked me if I was sure I didn't have any, so I had a look through, stepped through the code, and lo and behold, I did. While I was doing this process, we ended up having a discussion about how unit testing would help avoid problems like off by 1 errors, and would make iterating through the code and refactoring a lot easier.

That's what a good tech interview should look like, not expecting someone to write perfect code, first time.

On a side note, I didn't end up getting the job, since they had apparently hired someone the day before I came in for the interview. Apparently I managed to apply for the job the day they closed applications, but they asked if I wanted to interview anyway, out of courtesy.