I doubt you could find two that look the same on the inside, too many talented coders are needed to get to that point; but there's some good stuff by Sean Parent of Adobe on YT.

this resource exists purely for people to practice for systems design interviews. or at least, that's 99% of the use cases of this repo

Systems engineering is the discipline that got us to the moon, and builds advanced technology like military hardware.

For other large scale software projects, I think they tend to use enterprise software architecture patterns like service-oriented architecture (basically microservices) and ESB (basically kafka).

Architecture of open source applications, which has a free book version available on their site, has that info on some other large desktop applications .