This is incredibly true. I once turned 60kLoC of classic ASP in VBScript into about 20kLoC of python/django including templates. And added a bunch of features that would have been impossible on the old code-base. It turned the job from hellish (features were impossible to add) to very nearly boring (there wasn't much to do anymore). So with this newfound freedom I built some machines to automate the data entry and on…
"Tell me about writing a compiler" There's no way to interview for what you're looking for, but compilers seem to require both great organizational skills and some algorithmic chops. there's enough complexity you can't hide lack of one side or the other. Anyway, asking about building and enhancing a compiler seems like one of the ways to get insight about how people grow code. Every program is a seed. Is this the kin…
A compiler doesn't have that. It's blissfully old-fashioned, really: read files in, write files out -- no interruptions or real-time requirements. You could do compilers on punch cards.
In a way, the compiler is the most complex piece of software that you could imagine in 1960... But software has moved on and faces a different kind of complexity.
Hence I'm not sure if asking about compiler architecture is really representative of the organizational skills needed by today's software engineering.