http://www.joelonsoftware.com/articles/FindingGreatDeveloper...
http://www.joelonsoftware.com/articles/FindingGreatDeveloper...
I'm just suggesting that when an applicant like this exists before you, it makes more sense (assuming you're happy with their accomplishments) to confirm that these are indeed their accomplishments than to try to cram in some ad hoc heuristic for determining their range of skills in an hour or two.
And if my peers are any indication, the reason it's become so hard to hire senior devs is that no one wants to go through the headache of the interview process anymore once you've reached a moderately satisfactory job situation.
And you can't figure those things out just by looking at a resume or by quizzing them for hours until they break. You have to actually talk with them. Engage them in conversation. Learn who they are and how they fit into this field. Learn about their past experiences and their future goals. Then the question as to whether or not to hire them is easy.
Resumes are a starting point. Previous knowledge is a time-saver. Problem-solving and motivation is where its at.
*As a side note, most of my interviews were 30 minutes or less. I only regretted one hire, and I got rid of him pretty quickly.
That means, no onsite interview processes that require taking vacation days to complete mostly. Or off hours interview processes.