I was contacted by a third-party recruiter, who passed my CV along to them, and was then told to do the same unpaid test that others have mentioned involving parsing a crontab. It wasn't particularly difficult, but did take some time, and after doing it and submitting it, I waited a week and was then told that they decided to freeze their hiring for the year. They may not have even looked at the project, and certainly didn't offer any feedback on it. I find that totally unprofessional and the takeaway lesson for future applicants is - don't be surprised if they completely waste your time.

I did the first stage with the recruiter was a good experience, she told me with detail about the company, the project, asked about my experience and she answered the questions I had. However, the coding test was a bit vague, I missed more details about how to do it and what they expect (i.e. how is the input sent, in a file, in a console line...). In the end I got rejected after having reviewed the test without any kind of feedback about why I got rejected and what they found that was not right.