I remember a discussion on HN (I think) about the Skype windows client, where an ex-dev told tales about how horrible their code base is. It sounded like an engineers nightmare. They also employ(ed?) several obfuscation techniques and stuff like runtime memory encryption, just to 'protect' their protocol from being reverse engineered. I can imagine that things didn't improve much over the last decade and that their Android/iOS app doesn't look much better internally.

Wait, really? Have you used the same Skype that I've been using?

And yet here we are.

Skype wasn't originally written by Microsoft, so who knows how the code looks like. I know the linux client was god awful.

BTW, the old linux client (dating back to 2014) still exists and can be downloaded from the official site. It only supports text messages and files, and the messages don't show up in other clients for some reason as if they are not stored in the server side log. Can't explain that one.

Skype was developed by an outsourced team in Estonia.