Coding exercise as part of interview process
Unless you are a superstar programmer, you have to do a coding exercise as part of the interview process nowadays. I had a retired BBC journalist as a colleague at university. Very intelligent, focussed and an impeccable gentleman who could carry garish shirts in style. He gave me priceless advice on preparing my CV. He said - CV is your chance to get to the interview stage, keep it to the point. You get the whole interview to impress the interviewer(s).
Why am I giving you tips on CV?
Because, I think it is the same for coding exercises. The coding exercise is a way for you to get a face-to-face interview. So, don’t stray away from the requirements. It’d be lovely to hear about how you will architect the system, but that’s not the point of the exercise. There’s no need to go over the required and miss an important part. It is better to produce something close to the requirements. You can impress them in a face-to-face interview.