It's normal. A company that doesn't do this, unless it's tiny, is a warning sign. Why? Short answer: It's very difficult to work with incompetent colleagues co

It's normal. A company that doesn't do this, unless it's tiny, is a warning sign. Why? Short answer: It's very difficult to work with incompetent colleagues colleagues. Long answer: We don't rely on a credentialing process like other fields do. Some people lie on their resumes or embellish their skills. Other people overestimate their skills. As a result, employers have to determine competence in the interview process. A single coding question is often not enough. At a minimum bias can creep in, but also poor interviewer skill can make a good candidate appear poor, or could allow a poor candidate to pass. Furthermore, often companies need to screen for particular skills that are critical for a given product. Furthermore, I think it's useful to be exposed to everyone's communication style, and for everyone to be exposed to your communication style. Often that has more to do than just technical competence. FWIW: My wife is a pediatrician and her job interviews were mostly mutual interest. But, she had to go through a rather intense credentialing process. Our industry doesn't seem to trust credentials for reasons that I never understood, therefore, we tend to rely on employers gauging technical competency instead of a third party gauging technical competency.