Or, or you can do something like this.

But that isn't a huge security risk to your home, so it will never take off.

Hell. No.

We (Mrs. moriati and I) gave a set of keys to both a food delivery company and a pet feeding service so they could access our house when we weren't in. This was years ago, that said the deal there was that they were generally held by one person. This system would be a lot more flexible - what's needed is a return to fashion for vestibules.

Say it out loud ... vestibules.

I decided to Google image search that, to confirm whether a vestibule was an entrance hall or something more specific, and Google showed me medical pictures of vaginas. I kid you not.

That was, uhmmm .. unexpected.

You can have vestibules surgically removed.

Or make your delivery via the back porch.

"backdooring the frontdoor" sounds like a deviant sex thing but I can't work out what it would involve.

Never backdoor the front door. You can get an infection that way.

And it may raise your insurance premiums.