https://basecamp.com/shapeup/0.1-foreword

In software, everything is possible but nothing is free.

Diving straight into “what to build”—the solution—is dangerous.

We wanted a cycle that would be long enough to finish a whole project, start to end. At the same time, cycles need to be short enough to see the end from the beginning.

Losing the wrong hour can kill a day. Losing a day can kill a week.

We have to learn what we want by building it.
The solution doesn’t matter if the problem isn’t worth solving.

Teams discover tasks by doing real work.

By clicking through a core interaction early, they were able to validate that what they hoped would make sense in theory did indeed look right and make sense in practice.

Instead of one big hand-off, take turns layering in affordances, code, and visual styling.