Sorry Mikey but you're wrong. According to the OED not only is performant a word it does not mean what you think it means and its been around for roughly 200 years (as a noun).
performant
/pəˈfɔːmənt/
adjective: performant
functioning well or as expected.
"a highly performant database which is easy to use"
noun: performant; plural noun: performants
a person who performs a duty or ceremony.
Origin
early 19th century (as noun): from perform + -ant; the adjective dates from the 1980s.
Biting the hand that feeds IT
