> but what about the engineers who conduct technical interviews?

You will be lucky if they read your resume at all, and when they do, it'll likely be on their phone as they walk down the hall to the interview room.

Resumes are mostly to get past the HR filter, and maybe impress the hiring manager - the engineer interviewing cares how you perform in the room itself.

Also at a lot of big companies, interviewing is not for specific teams, so the odds of someone they haven't specifically headhunted ending up on their team is low.

There's no way to know whether that's the candidate's code or copy-paste or they paid someone else to do it, short of using interview time to evaluate it. However, employers also want to provide a level playing field to all candidates, including those without side projects, so there are common evaluation points that are used for all candidates for each interviewer, meaning that little or no time is left in the interview to have that discussion.

As an aside, unlike other comments, I do read all resumes of candidates that make it to the interview stage in detail and ask questions about it to try and get a sense of whether there's any inflation going on or not.

Nope. My company has a set slate of interviews. I am there to primarily get signal from my specific discussions/questions.

I rarely look at resumes before I start the interview. Even if I did, I’m not going to peruse the candidate’s GitHub profile. The majority are pretty sparse or not relevant, and not worth the effort.