Coding in interviews
I have gone to countless developer interviews at this point. And I have gotten jobs with zero technical tests and I have done technical tests. As with everything else in a job interview there are good and bad ways of doing it.
Everything in a interview will work better if you focus a lot on making everyone comfortable. Then you get a better view on the candidate, and the candidate gets a much better impression of the employer.
When you run a technical test, the most important thing is that everyone understand what the purpose of the test, and what you are looking for.