I sent my cover letter about the postdoc position. And after I got email back from my PI, I had a conference call with my PI. My PI asked me my background and my experiences in detail. After then, my PI introduced what this position was supposed to do in the current project. My PI asked me again about my feeling and how I could do this. So I think I answered quiet well.

I presented my PhD work and there was a brief question and answer session. They knew me already from my work and I had a collaboration with them, I also got a strong recommendation from my PhD supervisor, so I got the offer pretty easily.