Sublime

Pair programming dramatically increases the spread of knowledge throughout the team. Although specialties remain, and tasks that require certain specialties will usually belong to the appropriate specialists, those specialists will pair with nearly everyone else on the team.

This means that an XP team will probably not start with infrastructure, probably won’t select the database first, and probably won’t select the middleware first. Rather, the team’s first act will be to get the first batch of stories working in the simplest way possible.

The resultant code is designed and authored by both members. Neither can take more than half the credit.

prototype,

Problems start when you have more people than you need. You start inventing work to keep everyone busy. Artificial work leads to artificial projects. And those artificial projects lead to real costs and complexity.