Oura Senior System Engineer interview questions

Talent scouting person contacted me, and we agreed a 1h online interview. A couple of days later a team interview (1h) was agreed and held. Two weeks later a final interview date was agreed and it took place some days later with the team leader. All interviewers were encouraging and polite. In one week I was offered a job, and surprisingly the offer was valid only for one work day (+weekend).