performant

Short definition from Wiktionary

Adjective

1. 1
   Of or relating to performance.
2. 2
   Performing well; Capable of or characterized by a high or excellent level of performance or efficiency.
3. 3
   Performing well; Capable of or characterized by a high or excellent level of performance or efficiency: Characterized by a level of performance or efficiency that is adequate for or exceeds the expectations of end users.

Noun

1. 1
   Someone who performs something, such as a ritual; a performer.