Weekly roundup: diving into DDD

At Allbus, finally we have abandoned our archive-like modules and dived into something more complex, which comprehends invoices and money. [Essential] Complexity in behavior should not be feared in this case, as Brandolini taught us it is mandatory for applying Domain-Driven Design with some return on investment. A challenge is also adapting some practices, like a model free from the influence of database tables, to PHP technologies (we jumped from Doctrine 1 to Doctrine 2 just for that.)

Between transforming specification documents and the Domain Expert's Verb into unit tests and discovering tacit concepts of our codebase, I' ve written some article for you.
Practical PHP Testing Patterns: Prebuilt Fixture discusses test fixtures built in the bootstrap of the suite.
Why Twitter is not an RSS replacement sums up the issues with Twitter usage. For example, it's impossible to follow a conversation.
Practical PHP Testing Patterns: Lazy Setup explains how to lazy-create a test fixture such as a database connection.
TDD for algorithms: the state of the art is my take on what you can use Test-Driven Development for.