Meta Product Design interview questions

30 minutes phone screening, past work (portfolio) walk through and an app critique. Interviews were scheduled back to back. The hard part was waiting. It took a month for FB to finalize their decision after my final interview. This was ridiculous because they usually review candidates very quickly. After a month I was told that they placed me as a second choice and decided to give the offer to another candidate. If the candidate rejects the offer and they would give it to me. This is extremely unfair as it wasted my whole month as they kept placing me as a back-up.