[sailfrog]

We use a coding test as a part of the interview process for new developers and it works quite nicely. Note it is just one part of the process, though it can help sway a decision when we are on the fence (I have personally seen it push the decision both in favor of and against a candidate). Also the test is a solved problem, we don't ask candidates to do our work for us :) Lastly we put a 2 hour limit on the test. Depending on what language the solution is submitted in this may result in an incomplete submission which is fine. We don't want candidates to spend tons of time on it (it is pretty easy to tell when someone has disregarded the time limit) since two hours of work is enough material to gauge metrics that we care about.