If you are teaching something you're probably teaching it for >10 years. If every year you create 20 multi-part questions ("We have a factory producing boxes, what's the optimal size of box for X when Y"). You can then distribute a random question to every student in a similar bin of grade distribution. If a group of people are cheating they'll likely be in the same grade bin so this makes sure each cheater doesn't see the questions everyone else does.

You repeat this process every year for 10 years and now you have 200 questions. The next professor comes in and does the same but now also has 200 questions + answer guides.

With some basic programming you could make it automatically change the numbers (to "friendly" numbers that break up into round numbers) and have an infinite pool of challenging quiz, midterm, and final questions. If everyone gets different questions they cannot cheat by sharing answers. Only by sharing approach.