Meta Research Software Engineer interview questions

The recruiter contacted me on LinkedIn for a Research SW Engineer position with FRL at Redmond WA. Had the preliminary phone call with her followed by a C++ coding interview on the Phone. 2 days later they contacted me and wanted me for their virtual on-site interview. It consisted of 1 recruiter intro ,1 behavioral , 2 coding and2 system design , and one with a guy who filled in for the hiring manager. Aced all of them . A week later the recruiter sent me a one line email asking me to set a time for a phone call. A one-line-email would tell you the whole story, wouldn't it? Long story sort they rejected me and as they knew I did very well they came up with the canned answer that they had better candidates.