Degree doesn't say much, not even intelligence does.
If you want an experienced developer that can start right away, it must be someone that worked an extended time period with the specific technologies required, there is no alternative. Especially in software that could be anything.
The company I work for mainly just hires people for a month and then management gets feedback from the engineers before committing to someone. I think this process is quite nice and people seem to like it (they get paid of course). Applicants are subjected to the whims of engineers though, so you "need to be a fit" too. Advantages and disadvantages.
Fizz buzz is an easy example, but that is basically checking that someone knows the modulo operator. A lot of devs also lack basic "tricks" with bit operations. Ideally a developer is able to do that, but companies must be aware to offer resources to train people.