expert

a person with special knowledge or ability who performs skillfully

having or showing knowledge and skill and aptitude; "adept in handicrafts"; "an adept juggler"; "an expert job"; "a good mechanic"; "a practiced marksman"; "a proficient engineer"; "a lesser-known but no less skillful composer"; "the effect was achieved by skillful retouching"

of or relating to or requiring special knowledge to be understood; "technical terminology"; "a technical report"; "technical language"