What do top Ph.D. program admissions in Computer Science think of students who worked after undergraduate?
I work at the first "etc." in your list of CS departments, and I regularly evaluate graduate admission applications.

Rather than guess at the answer, I looked through my department's actual Fall 2019 PhD applicant database, and read the faculty comments on the applicants I found with degrees granted more than five years ago.  The non-traditional applicants that we offered PhD admission all had most or all of the following features:


They had excellent academic records from strong undergraduate programs (but not necessarily in computer science).
They did not have embarrassingly low test scores.
They had significant recent course work in computer science, typically as a non-degree student, with excellent performance.
They had strong reference letters from academic sources, either their old professors (who still remembered them) or from more recent instructors from non-degree classes.
Most importantly: They had worked in a research capacity during their time outside academia, either within their company or collaborating with academics.


(The first four points are not that different from successful traditional applicants.)

Non-traditional applicants that missed one or more of these features were viewed with more caution.  In particular, some otherwise strong non-traditional applicants without recent CS coursework (or equivalent work experience) were recommended for admission to our MS program instead of directly to the PhD program.  Again, this is not that different from traditional applicants.

So here's my advice: If your industry job does not have a significant research component, you are probably better off applying to MS programs first, as a stepping stone to a later PhD.  (Keep in mind that there are two types of MS programs in computer science: course-based/terminal/professional programs, and research-based/thesis programs.  You want the latter.  All online master's programs are the former.)  Even before shifting back to graduate school full-time, you should carve out some time to take one or two advanced courses as a non-degree student, and to interact with the instructors enough that they can serve as good references.

Always remember: The main thing that PhD admissions committees at top CS programs are looking for is compelling evidence of research potential.  As Buffy says, being a code-monkey at Microsoft or Twitter won't give you that.