CTFL-AT Agile Testing Fundamentals: Principles and Practices

Parul Dhingra13+ Years ExperienceHire Me

Senior Quality Analyst

Updated: 1/25/2026

Understanding the fundamentals of Agile testing is essential for passing the ISTQB CTFL-AT exam and succeeding as a tester in Agile environments. This guide dives deep into the core principles that differentiate Agile testing from traditional approaches, exploring how testing integrates seamlessly into iterative development cycles.

Whether you are preparing for certification or transitioning from waterfall to Agile, mastering these fundamentals will transform how you approach quality assurance.

The Agile Mindset for Testers

Shifting from Traditional to Agile Testing

Traditional testing often follows a sequential approach where testing is a distinct phase after development. Agile testing requires a fundamental mindset shift:

Core Agile Values Applied to Testing

Individuals and interactions over processes and tools:

• Face-to-face communication with developers
• Pair testing and mob testing sessions
• Immediate feedback rather than formal reports

Working software over comprehensive documentation:

• Executable tests as living documentation
• Focus on automated test suites
• Minimal but sufficient test documentation

Customer collaboration over contract negotiation:

• Testers participate in requirement discussions
• Direct engagement with product owners
• Understanding the "why" behind features

Responding to change over following a plan:

• Adapt test approaches based on feedback
• Embrace requirement changes as opportunities
• Flexible test prioritization

The Tester as a Team Player

Agile testers contribute beyond traditional testing:

Facilitation Skills:

• Lead three amigos sessions (developer, tester, product owner)
• Facilitate exploratory testing sessions
• Guide acceptance criteria discussions

Technical Collaboration:

• Review code for testability
• Pair with developers on test automation
• Contribute to continuous integration setup

Domain Expertise:

• Understand business requirements deeply
• Identify edge cases and scenarios
• Validate user experience perspectives

Whole-Team Approach to Quality

Shared Quality Responsibility

The whole-team approach means everyone contributes to quality:

Product Owner:

• Provides clear acceptance criteria
• Prioritizes quality alongside features
• Participates in testing activities

Developers:

• Write unit tests for all code
• Practice TDD/BDD when appropriate
• Fix defects within the sprint

Testers:

• Guide test strategy and coverage
• Perform specialized testing (exploratory, performance)
• Coach team on testing practices

Scrum Master:

• Removes impediments to testing
• Facilitates quality discussions
• Ensures testing is part of Definition of Done

Cross-Functional Skills

In Agile teams, skill boundaries blur:

Benefits of Whole-Team Testing

• Faster feedback: Issues found when they're created
• Better quality: Multiple perspectives catch more defects
• Shared knowledge: No single point of failure
• Reduced handoffs: Less "thrown over the wall" behavior
• Team ownership: Everyone cares about quality

Testing Throughout the Sprint

Sprint Lifecycle Testing Activities

Testing activities occur throughout every sprint phase:

Sprint Planning (Day 1)

Tester Activities:

• Clarify requirements and acceptance criteria
• Identify testing dependencies (data, environments)
• Estimate testing effort for user stories
• Highlight high-risk areas needing extra attention
• Ensure stories are testable before commitment

Questions to Ask:

• What are the acceptance criteria?
• What test data will we need?
• Are there integration dependencies?
• What is the risk level of this story?

During the Sprint (Days 2-9 in a 2-week sprint)

Daily Testing Activities:

• Test completed stories immediately
• Provide rapid feedback to developers
• Update automated tests
• Perform exploratory testing
• Participate in daily standups

Continuous Testing Flow:

Story Started -> Developer Builds -> Tester Tests ->
Feedback Provided -> Issues Fixed -> Story Completed

Sprint Review (Day 10)

Tester Contributions:

• Demonstrate tested features
• Share testing insights and metrics
• Discuss any quality concerns
• Gather stakeholder feedback

Sprint Retrospective

Testing-Focused Improvements:

• What testing practices worked well?
• What testing challenges did we face?
• How can we improve test efficiency?
• Are our tests providing sufficient coverage?

Parallel Development and Testing

In Agile, testing happens alongside development, not after:

Traditional Sequential:

Dev (Week 1) -> Test (Week 2) -> Fix (Week 3)

Agile Parallel:

Day 1: Dev Story A + Test Complete Stories
Day 2: Dev Story B + Test Story A + Fix Issues
Day 3: Dev Story C + Test Story B + Continue

Managing Test Debt

Just as code can accumulate technical debt, tests can too:

Test Debt Examples:

• Skipped tests to meet deadlines
• Outdated test documentation
• Flaky automated tests
• Missing test coverage for legacy code

Managing Test Debt:

• Allocate sprint capacity for test maintenance
• Track and prioritize test debt items
• Refactor tests during regular work
• Include test updates in Definition of Done

User Stories and Acceptance Criteria

Understanding User Stories

A user story describes a feature from the user's perspective:

Standard Format:

As a [type of user]
I want [some goal]
So that [some reason/benefit]

Example:

As an online shopper
I want to save items to a wishlist
So that I can purchase them later

INVEST Criteria for Testable Stories

Writing Effective Acceptance Criteria

Acceptance criteria define when a story is complete. Good criteria are:

• Specific: Clear, unambiguous conditions
• Measurable: Can be verified objectively
• Achievable: Technically feasible
• Relevant: Address user needs
• Testable: Can write test cases from them

Given-When-Then Format:

Given I am a logged-in customer
And I have items in my cart
When I apply coupon code "SAVE10"
Then my order total is reduced by 10%
And the coupon is marked as used

Checklist Format:

Acceptance Criteria for "Add to Wishlist":
- [ ] Logged-in users can add items to wishlist
- [ ] Wishlist persists across sessions
- [ ] Users can add up to 100 items
- [ ] Duplicate items are not allowed
- [ ] Users receive confirmation when item is added

The Three Amigos Session

The three amigos bring together three perspectives:

Session Outcomes:

• Shared understanding of the story
• Refined acceptance criteria
• Identified edge cases and scenarios
• Clear examples for development and testing

Risk-Based Testing in Agile

Product Risk in Agile Context

In Agile, risk assessment guides testing priorities:

Risk Identification:

• Complex or new technology areas
• Integration points with external systems
• Business-critical functionality
• Areas with historical defects
• Recently changed or refactored code

Risk-Based Test Prioritization

Sprint Testing Priority:

1. High-risk stories first
2. Stories blocking other team members
3. Stories with dependencies
4. Lower-risk independent stories

Adapting to Emerging Risks

Unlike traditional projects with fixed risk assessments, Agile risks evolve:

Signs of Emerging Risk:

• Stories taking longer than estimated
• Increasing bug count in an area
• Integration issues appearing
• Stakeholder concern about features

Response:

• Add exploratory testing sessions
• Increase test coverage in area
• Pair with developers for deeper analysis
• Consider spike stories to investigate

Definition of Done and Quality Gates

Understanding Definition of Done

The Definition of Done (DoD) is a checklist ensuring story completeness:

Typical DoD Items:

• Code complete and committed
• Unit tests written and passing
• Code reviewed and approved
• Acceptance criteria verified
• Regression tests passing
• No critical defects outstanding
• Documentation updated
• Performance criteria met

Testing in Definition of Done

Testing elements should be explicit:

Testing DoD Examples:

• All acceptance tests pass
• Exploratory testing completed
• Automated regression tests updated
• Test coverage meets threshold (e.g., 80%)
• Cross-browser testing completed (if applicable)
• Accessibility checks passed
• API contracts verified

Definition of Ready

Before work begins, stories should meet "Definition of Ready":

• Acceptance criteria defined
• Dependencies identified
• Test data requirements known
• Story is sized and estimated
• Mockups/designs available (if needed)

Continuous Improvement in Testing

Retrospective-Driven Improvement

Each sprint retrospective offers improvement opportunities:

Testing Retrospective Questions:

• Did we find defects early or late?
• Were our automated tests reliable?
• Did we have sufficient test coverage?
• Were acceptance criteria clear?
• Did we have environment/data issues?

Metrics for Agile Testing

Track metrics to guide improvement:

Learning and Adapting

Agile testers continuously learn:

• Experiment with new testing techniques
• Attend team learning sessions
• Share knowledge through pairing
• Apply lessons from defects found
• Adapt practices based on results

Key Exam Topics Summary

Must-Know Concepts

1. Agile Manifesto Values: Know all four values and their testing implications
2. Whole-Team Approach: Quality is everyone's responsibility
3. Sprint Testing Activities: What testers do in each ceremony
4. User Story Testing: INVEST criteria, acceptance criteria formats
5. Risk-Based Testing: Prioritizing based on product risk
6. Definition of Done: Testing elements in DoD
7. Continuous Improvement: Using retrospectives for test improvement

Common Exam Question Types

• Identifying which Agile value applies to a scenario
• Selecting the best time to perform a testing activity
• Choosing the appropriate level of documentation
• Recognizing whole-team approach examples
• Understanding Definition of Done components

Test Your Knowledge

Continue Your Learning

• CTFL-AT Complete Study Guide
• CTFL-AT Testing Techniques in Agile
• CTFL-AT Practice Questions
• CTFL Foundation Level

Frequently Asked Questions

Frequently Asked Questions (FAQs) / People Also Ask (PAA)