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

Scrum: Metrics, Scaling & Anti-Patterns

Key Metrics

Velocity       — story points completed per sprint (average over 3-5 sprints)
                  Used for forecasting only, not performance measurement

Burndown Chart — remaining work (story points) vs time within a sprint
                  Steep drop = good; flat line = blocked

Burnup Chart   — completed work vs total scope; shows scope changes clearly

Lead Time      — time from item added to backlog → delivered to production
Cycle Time     — time from item started → delivered (subset of lead time)

Sprint Goal    — qualitative success indicator: was the sprint goal met?

Scrum at Scale

• Scrum of Scrums: multiple teams sync via a meta-Scrum meeting — one rep per team discusses cross-team dependencies

• SAFe (Scaled Agile Framework): enterprise scaling with Program Increments (PI) — quarterly planning cycles across many teams

• LeSS (Large-Scale Scrum): minimal overhead — one Product Owner, one Product Backlog, multiple teams in one Sprint

• Nexus: Scrum.org's scaling framework — adds Integration Team to manage cross-team dependencies and integration

• Spotify Model: not Scrum — squads, tribes, chapters, guilds — often misunderstood as a prescribed framework

Common Anti-Patterns

• Scrum Master as project manager: tracking hours, assigning tasks, reporting status — kills self-organization

• Sprint as mini-waterfall: design sprint, dev sprint, testing sprint — defeats continuous integration

• Zombie Scrum: going through motions (standups, retrospectives) without inspecting or adapting

• Backlog as a wish list: thousands of items, never refined, no prioritization — PO is overwhelmed

• Velocity as KPI: pressures teams to game story points; velocity only valid for forecasting within one team

• No Definition of Done: "done" means different things → technical debt accumulates sprint over sprint

• Skipping retrospectives: "no time to improve how we work" — the team never gets better

• PO absent during sprint: team makes assumptions → wrong product built, rework in next sprint

Scrum vs Kanban

              Scrum                    Kanban
Cadence       Fixed sprints (1-4 weeks)  Continuous flow
Roles         PO, SM, Dev Team           None prescribed
WIP limits    Sprint capacity            Explicit per-column limits
Change        Between sprints            Anytime (pull new work when capacity frees)
Metrics       Velocity, burndown         Lead time, cycle time, throughput
Best for      Product development        Support, ops, maintenance, unpredictable work

Scrumban: hybrid — use sprint cadence but Kanban-style WIP limits and flow

Interview Questions

• What's the difference between Sprint Review and Retrospective? Review = inspect the product (stakeholders attend); Retro = inspect the process (team only)

• Who can change the Sprint Backlog during a sprint? Only the Development Team — PO cannot add new work mid-sprint

• What happens if the team can't complete all Sprint Backlog items? Incomplete items return to Product Backlog; the sprint ends on schedule regardless

• How do you handle bugs found during a sprint? Minor: fix within sprint. Major: create backlog item, prioritize with PO for next sprint.

• What's the PO's role during Sprint Planning? Clarify stories and acceptance criteria — but the team decides HOW much to take on