the same reason you trust external companies to do all sorts of other stuff for you: specialization. in the average case, they can probably do it better than your developers because it's their primary business.
Sure, but we are talking about a twofold trust problem here. Trust in an entity (external company vs internal developer) and trust in the work itself.
While I do see your point about trusting an external company which is specialized in the problem I’m trying to solve more than my own developers, I still have to transfer my highly sensitive data to them for which I have to trust them even more.
While I do see your point about trusting an external company which is specialized in the problem I’m trying to solve more than my own developers, I still have to transfer my highly sensitive data to them for which I have to trust them even more.