"Tell, don't ask" is easy to say, but how do you actually put it into practice?
AMA with Avdi, Part 1
Learn how to make deep copies of arbitrary Ruby object trees.
Freezing a Ruby object can leave you skating on thin ice. Learn how to render complex Ruby objects totally immutable.
Your code is a liability.
Learn about a useful tool for generating realistic-but-fake data for examples and tests.
Ask me anything!