The Pragmatic Comprehensive Senior SDET

What senior test engineers actually need to know.

Most automation books teach you the API. This one teaches you the decisions.

Why page objects turn into god objects around month six. When dependency injection through fixtures beats a BaseTest inheritance tower. How to validate a JSON contract when there's no OpenAPI spec — which, in the real world, is most of the time. When the Screenplay pattern is worth its ceremony, and when adopting it will quietly split your suite across two architectures.

Distilled from 20+ years of quality engineering at Apple, Netflix, PayPal, and eBay. 18 chapters, 80+ tested code examples, and honest trade-offs on every pattern — including the ones I'd argue against.

WHAT'S INSIDE

TypeScript and Playwright, at depth — essential and advanced TypeScript aimed squarely at test code, plus Playwright's key APIs and the patterns that hold up past a hundred tests.

Architecture that survives scale — composition over inheritance, generics and type safety, dependency injection with fixtures, API mocking architecture, and scaling to production.

Mobile, properly — the CommonFramework: one Appium test case driving both native iOS and Android, in Python. Plus a bonus chapter on Appwright and a benchmark appendix with full configuration disclosed.

API testing with judgment — typed contracts with Zod, schema validation with and without an OpenAPI spec, and an honest comparison of Karate vs. REST Assured vs. Playwright's own HTTP client.

Performance, end to end — JMeter, K6, and real user monitoring. Synthetic, load, and RUM.

The Screenplay pattern — a complete micro-framework in about 60 lines of TypeScript, a full checkout suite with zero selectors in the test body, and four enterprise failure modes, including a team that adopted Screenplay when they shouldn't have.

Senior craft — interview questions built on architectural reasoning, test data management and failure triage, AI-assisted testing and GenAI in automation, and device and wearable testing: the manual disciplines automation can't replace.

THE COMPANION CODE IS THE REAL DELIVERABLE

Two complete, runnable projects — not snippets:

CommonAppiumframework — a production-grade Python and Appium mobile framework, one test case driving both iOS and Android.

saucelabs_automation_typescript — the full Playwright and TypeScript Screenplay suite, framework through passing checkout tests.

Both verified against the Sauce Labs demo applications on real cloud devices. Your purchase includes access to the private Git repositories, and they are kept current as Playwright and Appium move — the repositories, not the printed page, are the source of truth.

EVERY COPY FUNDS REAL SCIENCE

100% of author royalties — from every sale, on every platform — go to Thirumoolar Chair Inc.

The Chair funds the peer-reviewed research of Dr. Sundar Balasubramanian (Department of Radiation Oncology, Medical University of South Carolina) on Pranayama — yogic breathing — and its measurable health effects, in studies with cancer survivors and their caregivers. The work is backed by more than $600,000 in NIH and National Cancer Institute and state research grants.

I don't make money on this book. Pay above the minimum and the difference goes to that research.

Learn more at tamilchair.org and pranascience.com/research.

To receive your companion repository access, forward your Leanpub receipt to support@aitestguru.com.