> Most engineering interviewees fail to advance because of cultural/personality/communication issues and not technical competence.
Not my experience. At least when hiring for programming positions, the typical fatal issue is that the candidate's coding is weak.
In my first role as a hiring manager, I didn't stress coding tests for candidates with long work history on their resume. Since then, I learned better.
I've seen candidates with anything between 1 and 15 years of full time coding work on their resumes fail to answer basic fizz-buzz level coding questions.
At least for the candidates I've seen, the biggest single reason why they get rejected is failure to perform the one main function their job requires: coding.