The PR changes 'backend' to 'engine' where engines are referenced, in order to be consistent with the rationalization of the architecture. However, some files still use 'backend', as they operate at an abstraction level, where 'engine' is an irrelevant implementation detail.
GitHub is out of sync due to issues with rebase. Closing this PR and opening an identical one will result in showing the 25 actually changes files instead of the 109 shown in this PR
The PR changes 'backend' to 'engine' where engines are referenced, in order to be consistent with the rationalization of the architecture. However, some files still use 'backend', as they operate at an abstraction level, where 'engine' is an irrelevant implementation detail.