Mustafayev was born on 13 June 1965 in the village of
Jujevan in the
Noyemberyan District of the
Armenian SSR. In 1989, he graduated from the
Baku branch of
Voznesensky Saint Petersburg State University of Economics and Finance. In 1990–1991, he worked as the Senior Accountant at Baku's Main Construction Department. In 1991–1992, he was employed as the Senior Accountant at
Spektr firm. From 1992 through 1999, Mustafayev worked as an auditor, senior tax auditor, senior state auditor and department director at the State Taxation Office in Baku. In 1999–2000, he worked as the director of department for economic analysis, accounting and tax forecasts. In 2000–2003, Mustafayev was the assistant to, and then department director of Economic Analysis and Accounting Office of the
Ministry of Taxes and in 2003–2005, he worked as the Senior Accountant and later as the head of Accounting Department at
State Oil Company of Azerbaijan Republic (SOCAR). He then served as the Vice President for Economic Relations of SOCAR from 1 March 2005 until 9 September 2006. He's believed to have restructured and significantly improved the accounting system at SOCAR. ==Political career==