Received wisdom is that if you spend time up front getting the design right, you avoid costs later. But the longer you spend getting the design right, the more your upfront costs are, and the longer it takes for the software to start earning.

Design should be easy in the sense that every step should be obviously and clearly identifiable. Simplify elements to make change simple so you can manage the technical risk.

A rational model of software is to design it quickly - the economic pressure to improvise presents an interesting challenge.

Kent Beck Quotes