I was always under the impression that Microsoft was *finally* doing apps in a proper sandboxed / modular way (something Windows should have done decades ago). However, it looks like even Win8 Modern apps were implemented in the wrong way.
It appears that many of them use some kind of shared process and I can't tell where the apps themselves are located in storage.
I did find an actual background process for the Netflix app. Task Manager says it's located in:
C:\Program Files\WindowsApps\4DF9E0F8.Netflix_2.9.0.29_x64__mcm4njqhnhss8
The "WindowsApps" folder doesn't appear in Program Files. When I try to get there through other methods, Windows tells me to click Continue to request permission to access the folder and then denies access. My user account is an administrator account, so I don't know why the folder is inaccessible to me.