Sure there is good science in personality research. The "Big Five" is a good example of a well validated model that passes the checks you would want for a scale (reliability, validity, explanatory power etc.).

Myers-Briggs is an example of a personality test that is highly flawed.

If you are asking specifically whether personality is a good predictor of job performance, then yes, there is evidence for that. However, an issue is that you can very easily lie about your answers on the test. So if you know what the "correct" answers are you can fake it. A good use of such tests would be when you don't know what the correct answers are.