I applied online and had not that formal mail correspondence (which is usual for job interviews) with two people which are from the team (none of them was HR). We agreed to have a Skype call to meet. They asked me about my experience but at the end they said this is just general call which they have with all applicants and that the interview will be scheduled at the end of the week. Two weeks later after no one has contacted me, I sent them an email to ask for the info about interview because I wanted to organize my time. After couple of days they informed me that the position has been filled. I think this is not very professional and I feel like I wasted my time in the first place.

It was a friendly interview, asked me about my previous experiences, nothing very complicated. However, I had to write an e-mail after about a week because I didn't hear back from them. It would have been polite to just send an e-mail informing me about the decision.