Kanban, Lean, and XP

Scrum isn't the only way to be Agile. Three more names round out the family, and you'll meet all of them: Kanban, which optimizes a smooth, continuous flow of work; Lean, which obsesses over cutting waste; and Extreme Programming (XP), which adds disciplined engineering habits.

You don't need depth on each — just enough to recognize them and know what each emphasizes. They share Agile's small-steps spirit but pull on different levers.

A quick contrast to anchor it: where Scrum serves work in fixed courses (a set menu every two weeks), Kanban is more like a sushi train — you take the next piece whenever you have room, in a continuous flow.

Kanban

Kanban drops fixed sprints in favor of continuous flow. Work is shown as cards on a board with columns for each stage, and the team pulls a new card only when it has capacity. Its signature rule is the work-in-progress (WIP) limit: a cap on how many items can be in a column at once. Limiting WIP sounds restrictive, but it's the whole discipline — it stops everyone from juggling ten half-finished things and forces the team to actually finish work before starting more.

To Do	In Progress (limit: 3)	Done
Add reminders	Fix streak bug	Edit a habit
Weekly summary	Dark mode	Delete a habit
Export data	Onboarding screen	Sign-in
…	(full — finish one before pulling another)	…

Lean

Lean comes from manufacturing and centers on one idea: maximize value while eliminating waste. In software, "waste" is anything that doesn't help the end user — features nobody uses, work that sits waiting, repeated effort, needless handoffs. Lean teams try to deliver fast, decide as late as responsibly possible (so they decide with the most information), and ruthlessly cut anything that isn't pulling its weight.

XP (Extreme Programming)

Extreme Programming is named for taking good engineering practices to their logical limit — not for being reckless. It adds concrete habits like pair programming (two developers at one screen), writing tests before code, integrating everyone's work continuously, and releasing in small frequent steps. Several of these — testing, continuous integration — get their own chapters later; XP is where they were first bundled as a discipline.

Mixing Them

In the real world, almost no team follows one of these purely. They blend — borrowing Scrum's sprints, Kanban's WIP limits, and XP's engineering practices into whatever fits. You'll hear hybrids named, like "Scrumban". The lesson isn't to memorize rigid recipes; it's to recognize the ingredients, because every real team mixes its own.

Cadence shows the blend. Most of the time they run Scrum sprints. But when a wave of bug reports hits, sprints feel wrong, so they switch to a Kanban board with a WIP limit of three — no one juggles ten half-done fixes, and bugs flow steadily to "done". When the rush passes, they go back to sprints. Same team, different tool for the moment.