I would say that using technical terms in a joking way is definitely a sign of enjoying one's job, and enjoying one's job is definitely a significant data point

I would say that using technical terms in a joking way is definitely a sign of enjoying one's job, and enjoying one's job is definitely a significant data point as to gauging whether one is good at it. If you can talk about your job without criticizing it and laugh, I would say you enjoy what you do and therefore that you do it well.