GuideAdvanced
Test Strategy and Quality Engineering
You can't test everything, so the real question is what to test, at what level, and how much. This guide teaches how to decide a project's test strategy and the foundations of quality engineering: quality as a discipline for the whole team, not just whoever writes tests. It covers the test pyramid and its critiques (the ice-cream-cone anti-pattern, the testing trophy alternative), risk-based testing (prioritizing by impact × probability), when a test isn't worth it and should be deleted, quality metrics beyond coverage (mutation score, flaky rate, defect escape rate), the flaky budget and suite health, and quality as a team discipline (shift-left, reviewing tests, the definition of "done"). It crowns the Testing guide ecosystem: it closes with a capstone project where you write the complete test strategy document for Reservo, backed by measured evidence.
- 64
- lessons
- 8
- modules
- English · Spanish
- available in
- Yes
- certificate
- Free
- access
Outcomes
What you'll be able to do
- Understand test strategy as a conscious decision: what to test, at what level, and how much
- Draw the test pyramid of your own suite and recognize the ice-cream-cone anti-pattern
- Prioritize testing effort by risk: impact × probability, and where bugs are most expensive
- Decide what NOT to test and calculate the real cost of writing, running, and maintaining a test
- Measure quality beyond coverage: mutation score, defect escape rate, flaky rate, and execution time
- Define a flaky budget and a quarantine policy to keep the suite trustworthy
- Establish quality as a team discipline: shift-left, reviewing tests, and who owns what
- Write the complete Reservo test strategy document, backed by measured evidence, as a capstone project
Before you start
What you need to bring
It's for you if...
- Senior devs or tech leads who decide what and how much to test on their team
- Teams with a large test suite who aren't sure it's well-focused (high coverage, few bugs caught)
- Devs who already know specific testing techniques and want the judgment to decide when to use each one
Requirements and materials
- The Testing Fundamentals & TDD Guide completed (or equivalent: pytest, TDD, basic fixtures)
- Experience maintaining a real test suite on a project of some size
- Recommended (not required): prior exposure to test doubles, property-based testing, and CI for tests
Content
The syllabus, module by module
Open any of them to see its lessons.
- 1. Module introduction: from writing tests to deciding the strategy
- 2. You can't test everything
- 3. What a test strategy is
- 4. The levels of testing and what each is for
- 5. The cost of a test
- 6. Quality is a whole-team concern
- 7. Explicit vs implicit strategy
- 8. Mini-project: sketch the test strategy for a part of Reservo
- 1. Module introduction: from measuring the shape to judging it
- 2. The test pyramid and why this shape
- 3. The three levels and their tradeoffs
- 4. The ice-cream-cone anti-pattern
- 5. The testing trophy and other shapes
- 6. Measure the real shape of your suite
- 7. Shape as a balance, not a dogma
- 8. Mini-project: measure and judge Reservo's pyramid
- 1. Module introduction: what NOT to test and why
- 2. The real cost of a test
- 3. When a test isn't worth it: trivial code
- 4. Don't test the library or the framework
- 5. Over-testing and duplication
- 6. The maintenance tax of a fragile suite
- 7. Deleting the tests that don't pay
- 8. Mini-project: audit and prune a Reservo suite
- 1. Module introduction: the suite is green, so what does that prove?
- 2. Why coverage lies
- 3. The mutation score as a measure of power
- 4. 100% coverage vs a surviving mutant
- 5. The other metrics: escape rate, flaky, time, MTTR
- 6. Goodhart's Law
- 7. What to really measure
- 8. Mini-project: measure the real power of a Reservo suite
- 1. Module introduction: the suite as an asset that must be kept healthy
- 2. Trust in the suite is the asset
- 3. The flaky budget
- 4. The quarantine policy with a ticket
- 5. The slow-test budget
- 6. The broken windows of a red `main`
- 7. The signs of a sick suite
- 8. Mini-project: diagnose and budget Reservo's suite health
- 1. Module introduction: from testing to quality engineering
- 2. Quality isn't just "QA's" job
- 3. Shift-left: the cheapest bug is the early one
- 4. The definition of "done"
- 5. Who owns the tests
- 6. Reviewing the tests in the code review
- 7. The strategy document as a living artifact
- 8. Mini-project: write Reservo's definition of "done" and test ownership policy
- 1. Module introduction: from the seven decisions to a single document
- 2. Section 1: the pyramid target, measured
- 3. Section 2: the prioritized risk map
- 4. Section 3: what NOT to test
- 5. Section 4: the target metrics
- 6. Section 5: the flaky policy and the suite health budgets
- 7. Section 6: ownership and the definition of done
- 8. Project: write the test strategy for Reservo
Common questions
What people usually ask
No limit. It's a free guide: come in whenever you like, as often as you like.
No. Modules run from easier to harder, but you can jump to the one you need. Progress is saved per lesson.
Whatever is needed is listed under “What you need to bring”, above. If nothing is listed there, you can start from zero.
In the Club's WhatsApp group, and every two weeks there's a live with an instructor where questions get worked through.
Yes. It's issued automatically once you finish every lesson, with a verifiable code you can share on LinkedIn.
Start whenever you like
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