Booz Allen Hamilton Full Stack Software Engineer interview questions

Got a call from HR about the position - was told that there will be 2 rounds. cleared first round on Monday. after a day my next round was scheduled the same week on Friday. It went pretty well. Interviewers seemed pretty cool and were happy. I was sure I would get the job. On Tuesday (next week) I get a call from HR that they are interested to make an offer. After following up again today (Friday) I was told that they hired somebody. Not a good experience for me. Watch out for false promises.