[simonsarris]

There's a certification that always seems to be overlooked in these discussions but seems to be much agreed upon and present in other discussions, though for some reason its rarely mentioned in this topic.

When hiring my company's policy is that a code sample is a perfectly acceptable certification, often far more acceptable and telling than some of the more expensive forms.

And I think that we should all think of code samples as such. Especially if the code is public, or accepted into a (large/open source) project. A code sample is a certification, and one that is literally put to use in a production system/application has got to be one of the most valuable kinds of certification - that is, social proof - that one can achieve.