If Sergey Brin applied for an engineering position at Google today, would he pass the requisite phone screening? Don't be so sure: While he might look good on paper, he'd probably have to brush up on his Python programming skills first. Even if he passed, would it tell his potential employer anything useful about the value he could bring to the company?
1. Recruiters and other non-technical people typically don't understand the questions they ask, and that leads to a one-way conversation. In addition, questions are often stated incorrectly, or without the originally intended context and as such suffer from lost-in-translation syndrome. Correctly evaluating a candidate over the phone takes longer than a typical "screening" interview, and should be done by equally tech-savvy individuals on the employer's side.
2. From the perspective of an engineer, if an employer asks a lot of trivial coding or algorithm questions, it usually means the job they're hiring for isn't going to be that interesting (activate the big-company-coding-job radar). Phone interviewers do occasionally ask deeper questions, but given the limited time of a screening interview, and the inability of a candidate to present code or design diagrams, they are often forced to ask trivial ones.
3. Intelligence assessments can be a good indicator of talent, but don't waste time asking them to solve puzzles pulled off the Internet: Look at SAT or GRE scores, school transcripts, or some other substantial proof of intelligence (or lack thereof). This kind of background on a candidate can usually be found without the need for a phone interview.
Only good engineers can accurately measure the skills of other good engineers, and it takes a lot of probing in an in-person, back-and-forth conversation to get there. A meaningful engineering interview has to be conducted in person, with multiple engineers, and over the course of several hours (if not an entire day). It's worth the effort.
VIA [gigaom]
