Approaches for technical challenges

  • verbal
  • written on paper or a whiteboard
  • typed


If you want to test the candidate’s ability to work in a team, you can pair them with somebody from your company so they can solve a problem together. This can let you see if the candidate knows how and when to ask for help and if they take ideas from someone else or are stubborn.

You provide the candidate with a laptop and they can call on their partner when they struggle to solve the problem logically or need a question answered (how to do split a string by more than one delimiter, why is my while loop not ending, why is nothing printed?)

Ideas for technical challenges

  • Reverse the letters in each word of a sentence.
  • Check if a word is a palindrome.
  • Fibonacci sequence - either a series of numbers or a given number at a position (the Nth number).
  • Check whether an IP address is valid.

As an extra part, you can require the challenge include reading input from or writing output to a file.


  • Ask the candidates the same questions, so you have a benchmark to compare against each other.
  • Write down your rating of their answers during the interview - rather than waiting until afterwards. We are biased towards being affected by the most recent answers.