Pathetic in one word. Wasted my time.

First recruiter approached me and scheduled one round. After clearing the first round, the second round was scheduled but later canceled.

After two weeks, another recruiter reached out and scheduled one more round. The interview went well. Again, they vanished.

I asked several times for feedback, but received no response. Later, they came back and said I was not shortlisted. No reason, nothing.

Stop wasting time, useless recruiters.

Explain OAuth and how have you implemented it?