Part IV – API Quality Engineering

Part IV develops API Quality Engineering from first principles.

Chapters

1. Chapter 1 — API Quality Engineering: Boundaries, Outcomes, and Evidence

   150 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Parts I–III, or equivalent experience with quality evidence, typed data, asynchronous behaviour, and service testing

2. Chapter 2 — Interface Semantics: HTTP, Representations, and API Styles

   170 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapter 1 and working familiarity with requests, responses, and structured data

3. Chapter 3 — Contract Quality: Schemas, Semantics, Compatibility, and Evolution

   165 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–2 and familiarity with structured JSON data

4. Chapter 4 — Stateful API Behaviour: Validation, Errors, Idempotency, and Concurrency

   175 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–3 and familiarity with HTTP request and response semantics

5. Chapter 5 — API Data Quality: Queries, Collections, and Representational Integrity

   170 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–4 and familiarity with JSON representations and HTTP request/response semantics

6. Chapter 6 — Identity at the API Boundary: Authentication, Authorization, and Safe Behaviour

   175 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–5 and familiarity with HTTP request and response semantics

7. Chapter 7 — Dependent and Asynchronous APIs: Events, Webhooks, Third Parties, and Controlled Evidence

   180 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–6 and familiarity with API contracts, state transitions, retries, and correlation concepts

8. Chapter 8 — API Reliability, Diagnostics, and Performance Evidence

   180 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–7 and familiarity with API contracts, state transitions, dependencies, asynchronous completion, and retries

9. Chapter 9 — Sustaining API Quality: Change Impact, Regression, and Production Learning

   170 minutes, plus the practical exercise · Status: Draft · Version: 0.1.0

   Prerequisites: Chapters 1–8 and familiarity with API contracts, state, data, identity, dependencies, diagnostics, and evidence limits

10. Chapter 10 — Capstone: API Quality Strategy and Evidence Portfolio

    300 minutes, plus independent portfolio refinement · Status: Draft · Version: 0.1.0

    Prerequisites: Chapters 1–9 and the ability to frame API risks, select evidence, and state limitations