Hr called me Monday and Interview was scheduled for Tuesday (next day). Interview had 4 rounds, the process was quick and all were done in a single day. Salary negotiation with HR also done. They asked me to join in 2 days, but i assured i would join 3rd day(from date of interview).They asked 1 day time to release offer letter, finally after 48 hours called me and said due to budget constraints we wanna adjust with internal resource. Then why did they interview me HR accepted that it was his mistake with out knowing the status of position, he called me for interview. Dont believe until offer is released.