After the work is submitted the following day, if it looks good then call them in for an interview and ask them what were the weak points of the solution. If the developer is good, they will have worked it over in their head for the next day or two, and will have an answer ready.
Asking questions about the work produced is a good way to identify people who cheated. Ask questions about why and what was your intent with this.
Yep; we did that too. The flow was something like:
- Phone screen with our HR rep to figure out if you're even remotely what we're looking for
- Takehome challenge to make sure you can code
- Engineer reviews the challenge and, if good, calls you to discuss the challenge and discuss your experience in depth.
- If good, come onsite to meet the team, do a couple 1-hour use-anything challenges, and answer a few higher level long-form questions.
- Offer.
Asking questions about the work produced is a good way to identify people who cheated. Ask questions about why and what was your intent with this.