Cognizant Sr. Associate interview questions

I had 3 rounds of interview. The final one is with the client. It was smooth. But had to wait long the offer letter. Eventually I got that. In fact I waited for months but it ended up well.

I have recently given interview to Cognizant for senior Associate role. It contained two technical rounds(one with cognizant technical team another with client). Both went well and i cleared both of them. Later during my HR round for offer letter discussion, recruiter asked me to join in 60days(This has been also discussed during initial telephony interview with Recruiter ). I agreed for that. But when i received offer letter which was almost after 2 weeks of HR discussion, joining date was mentioned as within 30 days. I mailed to recruiter regarding joining date(sent reminder mails as well). After 10days she updated that she is not getting approval for 60 days. I never expected such kind of output from reputed organizations like Cognizant and I really don't appreciate their recruiting process. If they were not ok with my notice period they shouldn't proceed further with my profile. Wasted my time. Never believe in cognizant offer letters blindly please make another offer as backup.