Close! Booby trap is the one you’re thinking of. Galaxy’s child is where he meets the real engineer from booby trap and Geordi is sad/surprised that she’s nothing like the hologram.
I watched it recently, in the first episode he creates a hologram representation of the designer and the computer fills in a pleasant personality. The real designer comes aboard a few episodes later and is very cold and hostile. She also accidentally finds the hologram of her. They end up being friends in the end.