I'm making a change in the software which should be unnoticeable to users. What would be a single word that describes it best? I'm looking for an adjective that fits into sentence such as 'This change will be _____ to the end user.'
In software and hardware engineering the term would be "transparent".
Some devops heavyweights release software updates thousands of times per day — often so transparently that their users are not even aware.
Transparent things can be noticeable. A sheet of glass is transparent/translucent, but may be very noticeable. More transparency leads to less noticeability (thus the answer above talking about 'so transparent' (transparent would not need a quantifier if it was absolute).
Things that cannot be seen are invisible.