Scrum: Roles, Ceremonies & Artifacts

Scrum is an agile framework for developing complex products through short iterative cycles called Sprints (1-4 weeks). It defines 3 roles, 5 ceremonies, and 3 artifacts.

The Three Roles

• Product Owner (PO): owns the Product Backlog, prioritizes items by business value, single point of accountability for the product

• Scrum Master (SM): servant-leader who removes impediments, coaches the team on Scrum, facilitates ceremonies — NOT a project manager

• Development Team: self-organizing cross-functional team (3-9 people), collectively accountable for the Sprint Goal

Five Ceremonies

Sprint Planning    — start of sprint; team selects backlog items and creates Sprint Backlog
                         Input: Product Backlog (prioritized), team capacity
                         Output: Sprint Goal + Sprint Backlog

Daily Scrum        — 15-min daily sync; each member answers 3 questions:
                         1. What did I do yesterday?
                         2. What will I do today?
                         3. Any impediments?

Sprint Review      — end of sprint; team demos working software to stakeholders
                         Inspect the increment, adapt the backlog

Sprint Retrospective — team reflects on process (not product)
                         What went well? What to improve? Action items for next sprint

Backlog Refinement — ongoing (not official Scrum ceremony); PO + team estimate and clarify
                         backlog items before Sprint Planning

Three Artifacts

• Product Backlog: ordered list of everything needed in the product — managed by PO. Items called PBIs (Product Backlog Items) or User Stories.

• Sprint Backlog: subset of Product Backlog selected for the Sprint + the plan to deliver them. Owned by the Development Team.

• Increment: sum of all completed PBIs that meet the Definition of Done. Must be potentially shippable at end of every Sprint.

User Stories

Format: "As a [user type], I want to [action] so that [benefit]"

Example:
  As a registered user, I want to reset my password via email
  so that I can regain access if I forget it.

Acceptance Criteria (Given/When/Then):
  Given I am on the login page
  When I click "Forgot Password" and enter my email
  Then I receive a reset link within 2 minutes

Story Points: relative effort estimate (Fibonacci: 1, 2, 3, 5, 8, 13, 21)
  - Not hours — account for complexity + uncertainty + risk
  - Baseline: agree on a "1-point" reference story

Definition of Done (DoD)

• Team-defined checklist that every Increment must satisfy before being "Done"

• Typical DoD: code written, code reviewed, unit tests pass, integration tests pass, no new tech debt, deployed to staging, PO accepted

• DoD is not the same as Acceptance Criteria — DoD applies to ALL stories

• If an item doesn't meet DoD, it goes back to the backlog — it's NOT done