Feature of building computer programs, we hear (4)
I believe the answer is:
apse
'feature' is the definition.
(I have seen 'architectural feature' mean 'apse' so perhaps 'feature' could also mean 'apse')
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for apse that I've seen before include "place in church" , "In sacred space" , "Recess at eastern end of a church" , "Niche in church" , "Part of a church with the altar" .)