right up (one's) alley

Ideally suited to one's interests. Anna loves watching movies, so I'm sure she'll go to the film festival with you—that's right up her alley. This course seemed right up my alley when I signed up for it, but it ended up being dreadfully boring.

Also, right down one's alley. In one's specialty, to one's taste, as in Writing press releases is right up her alley, or He loved opera, so this program of arias was right down his alley. These idioms use alley in the sense of "one's own province," a usage dating from the early 1600s. [First half of 1900s] Also see cup of tea.

If something is right up your alley, it is the kind of thing you like or know about. This should be right up my alley but, despite the film's special effects, I found it rather boring. I thought this little problem would be right up your alley. Note: You can also say that something is right down your alley. I'll need whatever information you can turn up within the week. This case seems right down your alley. Note: The usual British expression is right up your street.

To be in one’s particular specialty or to one’s precise taste. The word alley has long been used for one’s special province; Francis Bacon so used it in his essay Of Cunning (1612): “Such men . . . are good but in their own Alley.” Up one’s alley, however, is a twentieth-century turn of phrase. Margaret Carpenter used it in her novel Experiment Perilous (1943): “It isn’t up my alley at all.” See also not my cup of tea.