The summary.
TESTERS OWN INFORMATION ABOUT RISK; THE TEAM OWNS QUALITY
Assigning quality to testers absolves everyone else, and defect counts used as measures make the relationship adversarial.
TEST CODE IS CODE
Poorly written test code becomes unmaintainable faster than production code, and a suite nobody can maintain is eventually abandoned.
DOMAIN KNOWLEDGE REVEALS DEFECTS A SPECIFICATION CANNOT
Many serious problems are only visible to someone who understands the business — which is why that route into testing works.
MORE TESTING AT THE END DOES NOT IMPROVE QUALITY
It detects at the most expensive point. Clearer requirements, review before building, and faster feedback prevent instead.
Small frequent changes are easier to review, test, reverse and locate.
WITH LIMITED RESOURCES, AUTOMATE ONLY WHAT MUST NEVER BREAK
Then add a test for every defect found in production — it grows the suite exactly where defects occur.
Static analysis and dependency scanning cost almost nothing and find real problems.
PRIORITISE DETECTION AND FAST REVERSAL ABOVE MORE TESTING
It bounds the damage of everything you did not test.
