How to win the coding interview

My gut feeling tells me is because i am a rather ugly guy and also somewhat of socially inept, so i should make a bad impression. Currently working in losing some weight and trying to improve my social skills.

However, if you claim to be an expert in modern C#, you should write modern C#. To use my example, surely between string parsing, time calculations, collection handling and loops there is SOMETHING in there you use on a daily basis and can demonstrate your claimed ability write in a modern way.

I picked a small example, I don't actually know if we're moving forward with the candidate or not (I looked at the code but I've otherwise not been involved in the interviewing). For what it's worth, we have gone forward (and even hired) people that did poorly on the coding test, because through talking to them, they clearly know what they're talking about, and they could explain why they did badly.

However, I've seen many times where someone can't sufficiently explain what they can do or accurately describe things they know about, can't write code in a coding test (even if allowed to finish without time limit), and don't have any open source profile (eg, code published on github).

I don't expect everyone to be able to write SQL JOIN statements, but I do expect people that are "database experts" to be able to. If you claim to have an "expert level understanding of network protocols" you had better be able to explain to me the difference between TCP and UDP (and no, "UDP is more secure, TCP is faster" -- a real answer I got once, from someone with 15 years experience -- is not a good answer, even if it wasn't backwards).

How do you hire someone like that? It could be just me and/or my team: none of us can communicate with this person sufficiently, while they'd be okay with another team... but that in itself is probably reason to be a bad hire for us (and them).

Using a regex is overkill for the simple rejection of invalid characters. The job could be done in a single loop with worse case runtime n/2. Sure his solution is still linear time but he did ask for optimal.

It just goes to show that you can't win the interview game because everyone looks for different things. There is definitely good advice in this article though.

The problem though I have with code challenges, is when you get rejected, and they offer ZERO reason why they rejected your code, despite the fact you may have spent a whole fucking week working on it, doing the best you could. I have outright asked why my code was rejected, and I have NEVER gotten a response. Pure bullshit.

The other problem, is that most of the time they tell you not to use external libraries, which I get why, if they want to access your algorithms or data structure skills, but this is stupid, because you likely shouldn't rewrite libraries that do a better job than what you can code in a short time, and in any real world scenario, i would use all the libraries I could to write less code. Its better to test those things via white board. In some cases, I would reject you based on you not knowing about standard libraries.

I had one take home test, that was basically, write a database like thing in ruby to process and query an input file with dates, names, etc, you can't use any gems. If I used external gems, I could finish the assignment in few lines of code, without external gems, i have to do all this bullshit i would never do in a real world scenario.

Woohooa, cowboy. The language of palindromes is a classic example of a context free language that is not possible to describe with a regular grammar, such as accepted by a regular automaton... in other words a regex.

In Recruiter-Parseable English (RPE): you can't decide whether a string is a palindrome using a regex. It's impossible. Like, maths-impossible.

You can use regular expressions to compare strings while you decide whether a string is a palindrome but you can't do the whole thing in one regex.