Not Invented Here
The reflex to reject external solutions and rebuild internally — because trust, ego, or genuinely weird requirements. The syndrome's monument is the in-house tool that three vendors sell better.
Heard in the wild
“Classic not-invented-here: they rebuilt the ticketing system. It's worse.”
Tone check: Professional
Sometimes justified (core differentiators), usually expensive. 'Buy for parity, build for advantage' is the sane default.