This approach shifts the effort on constantly changing the source JSON data and specification on how it needs to finally look to the client. Lazy devs will inevitably post solutions online.

This approach also requires the client to implement ratelimiting, but you could fix that by having the data POSTed to your servers instead.

I unfortunately can't remember the name of it, but a service was presented on here a while ago that presented a series of security challenges then connected successful applicants with employers and managed the whole process. Methinks that's the right way to do this kind of thing.