Vangelis Bibakis recently gave two presentations to Joomla Day Greece.
In the first presentation he talks about MainframePHP, the framework we use to create web applications. The first parts of the presentation are a basic introduction with case studies and performance data. He goes into detail on how Mainframe compares to external libraries which provide similar functionality. This is also a great intro to people who are getting started with Mainframe and want to see how it implements concepts like theming and modularity.
In the How to get the tech job of your dreams presentation he explains why you should not have a CV and how to write a great cover letter.