He served as a judge in Ramallah, Jericho and Hebron Magistrates' Courts for nearly eight years. He has worked as a Senior instructor at the Law Institute of the Education program at the Law institute of Birzeit University since 1999. He worked as assistant to the Attorney General at the Ministry of Justice, and he also served as High Court judge and Appeal court judge and then the Director General of the Palestinian Judicial Institute. He was appointed Chairman of the Board of the Judicial Education Committee until he became Vice-President of the Supreme Constitutional Court in 2016.
Mubarak received his bachelor's degree in law from Beirut Arab University in 1975. He received a degree in judicial training from the University of Reno-Nevada in the United States of America. He received a similar degree in judicial training from Birzeit University and received a degree in the development of program skills Prosecution of the United States Department of Law (USDOJ).