Slicing work small

We cut work into thin slices that each go all the way through the system and leave something usable behind. A slice is vertical: a sliver of real capability, top to bottom, rather than a layer built on its own.

This provides a testable end-to-end change that can be proven in production without spending lots of effort before something can be validated.

Vertical, not horizontal

A horizontal split, building the whole database, then the whole interface, then wiring them together, delivers nothing anyone can touch until the very end, and hides integration risk until it is expensive to find. A vertical slice does one small thing end to end, so it can be shown, tested and learned from straight away.

What good slices look like

• Independent: it delivers something on its own, even if thin.
• Small: you can finish it inside a cycle, ideally a few days.
• Testable: you can tell when it works.
• Ordered by risk and value: do the scary, valuable slice early, while there is time to react.

Watch out for

• Slices that are really tasks in disguise (“write the model”) with no outcome a user would notice.
• A first slice so ambitious it is a project of its own. Start with a walking skeleton, the thinnest thing that runs end to end, and grow it.