Confused about interview outcome; how can I gauge my performance?

I have been at 3 job interviews in the past few weeks and I am a software professional with 6+ years of experience. I get a good feel during the interview and afterwards and feel positive about the outcome but I have been rejected all 3 times. The recruiters call and tell me that I have a good experience and blah blah but they decided to go ahead with a different candidate.

I am confused as I am not able to point exactly what must be happening that causes the negative outcome. According to me I prepare as much as I can and I am not sweating it at the interview itself and manage to answer all questions with confidence. Now, I am not even sure that all these companies were really interested in hiring or just plain wasting my time.

How do I gauge really how the interview went so that I am not this confused in the future?

Now, I am not even sure that all these companies were really interested in hiring or just plain wasting my time.

Seems to me that these companies took the time to call you back to inform of the negative result, something many companies don't bother doing. This suggest that they were not looking to waste your (and their) time.

How do I gauge really how the interview went so that I am not this confused in the future?

I feel that you are taking this a bit negatively.

You say you performed very well and felt that you delivered a good interview. You also say that, when they called you back, they mentioned you were a good and experience candidate even though you were not selected.

These things tell me that your performance was not bad (in fact, it was good), and that you didn't land the job only because the other candidates were a bit more experienced (or willing to take less pay).

I suggest that you don't give up, and keep applying. You mentioned that these were 3 instances... most of the times one has to apply several times (way more than 3) to land an offer, so don't lose your hopes now. Keep focusing and delivering good interviews as you have been doing and you will soon get an offer you like. Good luck!