Where is the plant growing and what was it originally labelled as?

I had asked for kerria. Definitely not that! I planted in partial shade, but want to make sure that's ok. I also have deer, sigh.

My best guess is some type of serviceberry, but I'm not sure

It could be Aronia, not sure about winterberry, as it looks different than my other ones. Are the leaves finely toothed like mine?

Here is a page with many clear closeup photos of Ilex verticilata (winterberry) so you can see growth patterns, leaf teeth, and fruits. For me one of the key characteristics of the winterberry is that that the fruits are on very short stems and so grow almost against the branches, unlike the Aronia which has longer stems. I can't tell from your photo how the berries are arranged.

The stems seem a little longer, so I'm voting aronia - thanks!

Red choke-berry for me also - except I am not sure the leaves and habit are 100% there. Where it can get tricky is that red and black cross to produce intermediate plants, if the fruits of yours become quite dark later hybridity may be involved.

Right^. What does make me think Aronia is the fall coloration that's starting to show up in that specimen. While only just starting, when full-blown, one of the great ones for fall color. I'd like to see a little more gloss on those leaves, but hey, it is fall and things are senescing.

+oM

Plant structure is that of choke-berry. I don't think red choke-berry is as glossy as black.

Red fruits and red autumn color = A. arbutifolia

Purple fruits and red autumn color = A. x prunifolia

Black fruits and yellow autumn color = A. melanocarpa

with cultivars of "black" choke-berry producing red autumn color belonging instead to A. x prunifola.

I'd also like to mention I've thought during this discussion your plant may belong to this particular cultivar. Although it produces red fruits, has been sold in the States as A. arbutifolia 'Brilliantissima' it is considered to be of hybrid origin.

https://www.rhs.org.uk/Plants/43102/i-Aronia-i-%C3%97-i-prunifolia-i-Brilliant/Details?returnurl=%2fplants%2fshrubs%3faliaspath%3d%252fplants%252fshrubs