Test Case Author — tests that actually catch bugs

Write test cases that ACTUALLY CATCH BUGS — not tests that go green while the shipped feature is 100% broken in production. Language- and framework-agnostic. Teaches the senior discipline behind a real green-but-broken incident: test the REAL artifact (invoke the actual exported function / hit the real endpoint / run the shipped binary, never a hand-rebuilt copy of the payload/schema/SQL the code is supposed to produce); assert the behavior/content CONTRACT (the value is correct, N inputs → N outputs, the field is populated, the script/encoding is right), not liveness ("returns 200", "didn't throw"); prove RED before green; hunt SILENT failures (swallowed catch, fallback-…