Guillaume M. had a bit of a problem in that for whatever reason delivery people can't get into his apartment complex with an NFC master pass. They call to ask to be let in, but Mr. M. is generally gone during the day, presumably at work. This then means he has to go get the packages, making at least the last part of the delivery service somewhat pointless.
The good news, since he lives on the third floor, is that when he’s home he can just press a button to let people up and doesn’t have to traipse down then up the stairs for the assist. If only there was some way to buzz people in remotely... Naturally hacking ensued, with the important restriction that since he doesn’t actually own the place, he has to be able to put things back in place when the time comes.
A quick non-destructive(?) disassembly of the intercom/lock controller revealed that he only needed to connect two lines to let someone in. This was taken care of remotely using a Raspberry Pi Zero W and a Telegram bot to trigger a relay board and open the door. The build also involves a generous amount of duct tape, with the Raspberry Pi powered by a voltage divider from the intercom itself. While we can’t necessarily recommend this type of project, and have to wonder what maintenance people will say at some point in the future, it's still an impressive hack!