Kevin Rutherford talks about the challenges of refactoring Ruby code, and his open source tool 'reek' which automates the discovery of certain code smells in Ruby code.
In this interview from OOPSLA 2007, Michael Stal talks about architecture refactoring. He describes what architecture refactoring is, its relationship to code refactoring and patterns, and he gives real world examples of how architecture refactorings have been done and when not to do it.
Debate sprang up at JAOO '07 around Bob Martin's assertion that "nowadays it is irresponsible for a developer to ship a line of code he has not executed in a unit test." In this InfoQ video, he debated with Jim Coplien on this and other topics, including Design by Contract vs. TDD and how much up-front architecture is needed to keep a system consistent with the business domain model.
Ramnivas Laddad talks about domain aspects, how aspects fit in the design phase, how to model aspects in UML, how to enforce policies with Aspects, how he used Aspects to diagnose production problems including touch threading problems, and using aspects to simplify design pattern implementation.