It's an interesting interview, actually recorded on 2022, even before CHM published the source code, and it's only about 30 minutes long.

I read some of the source code when it was released. Having the process ID as part of the window data structure makes me sad for what could have been on the Mac.

The RAM limitations of the original Mac coupled with some naive engineering decisions (and then terrible engineering management) crippled macOS for the following two decades.