Coding challenges are getting very popular now because they save time during hiring processes. Recruiters use them to filter out candidates. Usually having a bad answer is better than an incomplete one. For that reason it is important to start with a simple solution and iterate over it.<p>One frustrating thing in my opinion is that coding challenges only measure CS skills like data structures, DP, graph. While important those are not as relevant as more specific knowledge like HTML5, iOS, Android, etc.