I've done interview assignments a few times. In every instance I made it clear I needed a 2-3 weeks to complete the assignment (which was < 8 hours of work) due to my schedule. They never had a problem, and the interviews advanced to the next stage after they reviewed my submission.
I think most people are ok spreading 8 hours of work over a couple weekends. Paid shows the company is more respectful of your time, but in the end if they're taking up much of your time they should absolutely be flexible, or they will definitely pick-up a selection bias in their candidates.
I think most people are ok spreading 8 hours of work over a couple weekends. Paid shows the company is more respectful of your time, but in the end if they're taking up much of your time they should absolutely be flexible, or they will definitely pick-up a selection bias in their candidates.