Ruby Articles
« Please Do Not Break Into
If you are using an Object-Oriented language (writing code in a DSL can change things a bit, it depends on the DSL) you should specify and verify the objects themselves and not how they are implemented.
« Slides: What I Have Learnt Working With Startups
Slides from RailsCamp Hamburg 2011
« Clojure: Maps Are Not The Answer
When you are creating long-lived abstractions, you should consider using of the many good options of data types provided by Clojure and not just plain maps.