Runnable, MIT-licensed source for every chapter of The Staff Android Engineer: Designing, Diagnosing, and Evolving Android Systems by Rajesh Pattanaik, a book for experienced Android developers preparing for staff, principal, lead and architect work and interviews.

Book, free sample chapters and purchase: thestaffandroidengineer.com

• book-companions: the chapter-to-repository map, frozen first-edition tags and the compact source download.
• commerce-app: Common Goods, the offline-capable shopping application the main investigations evolve across Chapters 0–29.
• casebook-companions-code: the twelve Mobile System Design Casebook apps (Chapters 33–44), each with a controlled local backend or simulator.

Application source, learner and reference implementations, tests, build files, required assets, licence notices and minimal setup instructions. Chapter prose, exercises, written solutions and the reader guide are part of the book. Each repository's first-edition-2026.10 tag matches the first edition.

Use JDK 27 and each repository's pinned Gradle wrapper. Report reproducibility problems or errata through the book-companions repository's Issues, identifying the chapter and edition without posting paid chapter text.