Either you have to pass ALL the test cases for all 3 questions, or they are looking for a specific coding language/pattern. There's not much time to go back and optimize or improve your code so try your best to write optimized code from the beginning. You may consider coding in GO or TypeScript / JavaScript since their stack is Go, React. I did the assessment in a different language, and my solution for last question didn't work for a few test cases (edge ones). By the time I figured it out, the time was up. They decided to not continue with me.