"The concern is potential employers trying to bilk free work out of developers." If the coding exercise looks like something that is of this sort, then I guess

"The concern is potential employers trying to bilk free work out of developers." If the coding exercise looks like something that is of this sort, then I guess consider whether you want to work with that employer. From an employer perspective, this is the worst source of getting something built. A candidate should be researching the companies submits his resume/CV too anyway. "If it becomes widespread, we'll just see phony developer put their assignments up on rent-a-coder and ask for a crib sheet to study so they can withstand a technical interview on what they've created." If that were feasible, I'd suggest the employer would much rather hire the rent-a-coder instead of the one paying him. That's a win for the employer there too, since they'll be able to offer the rent-a-coder guy far more than the scratchings he gets as a rent-a-coder. The ability to predict in advance a sufficient range of questions as to forearm a candidate will border on the mystic. Coding exercises aren't a mouse in a maze puzzle, they are a starting point for gauging web development ability. The companies that use coding challenges as a way of creating production ready material are going to be amply supplied by the rent-a-coder approach you outline. And the technical interview part of the test is probably geared with a formulaic approach that can be guessed. In that case, this candidate and that employer are well matched. But not every candidate needs a rent-a-coder to pass a technical test, and not every company uses those tests to create production ready websites and applications. A good candidate can sniff a bad employer just as well as vice versa. If a company seems to be asking for production ready material, then walk away. If the test seems on the up, you'd better have a very good reason for refusing.