Verizon Sr. Software Engineer interview questions

Applied through a job portal and had a initial HR discussion about the role, company and benefits. A week later a telephone chat was scheduled with a director and it was quick and nothing difficult. A week later onsite interview was scheduled and had face-face with 5 interviewers. Most of the questions were on coding, design and patterns. Programming was easy and questions were mostly Fibonacci, reverse a string, palindrome type. I had nice conversation during the interview and they posed some of the challenges and problems they are facing and i could mention few of the design aspects and patterns which could solve the problem. Overall it was a nice experience in interview. Result: Rejected me, It was a bit of SHOCK for me as I did very good in interviews and could not recall what went wrong.