This is an old Java coding test used at NYSE Technologies (by the team descended from the TransactTools acquisition) around 2007 - 2010 or so.
I think it is a pretty good test and could be adapted to other languages. It is a good example of a "can you actually code?" test, without making the subject invert a binary tree or detect a circular linked list.
Or implement Fibonnaci sequence. Recursively. Seriously people, can we stop using that one? Ditto for Factorials.
(And don't get me started on Fizzbuzz).
It's important to note that I didn't create this project. All credit goes to Ben Ragheb aka @benzado, who had a fantastic knack for identifying the best candidates. He also devised a terrific phone screen that focused on communication skills, not "writing code over the phone" or answering rote programming minutiae. He was key in assembling one of the most talented engineering teams I've had the pleasure of working alongside.
How we administered this test:
This was not a "take home" test. It was done on-site, on a laptop provided to the candidate. At the time, Macbooks were not so pervasive, so they used a (shudder) Windows laptop. Hence the done.bat script in the root directory.
The candidate had one hour to complete the test. We provided a downloaded copy of the Java SDK javadocs, but no Internet connection. The laptop had both Eclipse and IntelliJ installed and ready-to-go.
Most candidates completed the test in the given hour with unit tests passing. One enterprising candidate did this by modifying the unit tests (they weren't hired).
If you want to see a similar coding test I developed for Scala, see noahlz/tactical-engineer-test.
I also wrote a blog post on my philosophy of coding tests. See: Make them Prove they can Code - And Actually Do the Job (Novus Tech Blog)
I've chosen to license this under the Unlicense, but that could change at any time. The intention here is that it's a fun throwback / gag, and might be an hour or two of coding for someone learning Java. If you want port it to another language and let us know, that would be fun too.