Large software projects cannot be built without some amount of analysis and design. But not all parts of the system require the same amount of design. Some may not require any upfront design at all. Others require a few minutes of architecture discussion; some require weeks of analysis, documents and review. A balance is necessary: too much design and you're delaying the project; too little and you will add technical debt which you'll have to pay in future rewrites and painful maintaining. How do we decide when design is needed and how much of it is needed? How do other Agile projects do it? In this talk I discuss what the Agile literature has to say about architecture and how we can answer this question.