General computing term.
Wiktionary: "Capable of achieving an adequate or excellent level of performance or efficiency."
Techopedia: "Performant means that something is working correctly or well enough to be considered functional. In a technology context, this term is believed to have originated with programmers seeking a concise word to express that a system or program will work, but may not yet be optimal. Performant may have come from a portmanteau of performance and conformant - as in working and meeting existing standards."
Stackoverflow: "Performant is a word that was made up by software developers to describe software that performs well, in whatever way you want to define performance."