Get a email directly ask me to interview onsite. First had a short chat with the manager. Got some idea about the position then short introduction about myself. Then, talked to the team leader. Asked some question concerned with the skill I claimed on my resume, then a easy physics question. Then another short chat with a developer in the team. Asked me some SQL question. Last, a conversation with HR. Seems like you already get an offer when you are able to see HR.