Use 'metier' to emphasize someone's exceptional skill in a field or activity. Designing user-friendly interfaces is clearly her metier.
Pro Tip 2/3
Positive Connotation
'Metier' often implies that the person not only excels in the activity but also enjoys it. After trying different jobs, he discovered that teaching was his true metier.
Pro Tip 3/3
Not Just Jobs
'Metier' can refer to hobbies or roles that a person is particularly good at, not just paid work. Organizing community events turned out to be her metier.