The first slice cuts all the way through the functionality. Once they build all those pieces, they can see the functionality working from end to end. It wouldn’t work in all the situations it needs to, and if they shipped to users this way, those users would howl. But Mike and his team will be able to see the software running end to end. They’ll be able to put real data in it to see how well it performs, and they could apply some automated testing tools to it to see how well it scales.
