After completed his Diploma in State-Accounting program from Indonesian State College of Accountancy (STAN), a government-affiliated college in Indonesia, in 1999, Hermawan appointed as a government employee in Directorate General of Taxes (DGT). Then, he received his Bachelor degree and professional degree as an Accountant from the same college in 2004. In 2007, he received a scholarship from Indonesia Government to pursue his master degree in Public Policy and Taxation at the Yokohama National University, Japan. On the same occasion, he also participated in the Internship Practicum Program at the National Tax College (Japan).
Most of his career at the DGT was in the field of tax audit and law enforcement. Since 2010 until 2016, he works in tax investigation area, formulating tax investigation policy, and to supervise tax investigation activities. Since 2016, Hermawan was transferred to the digital tax forensics areas. Apart from his main duty, Hermawan was heavily involved in the Indonesian tax reform program and the formulation of the strategic planning of DGT. In 2015, Hermawan received a doctoral scholarship from the Indonesian Endowment for Education (LPDP) and in 2017, he joined the doctoral researcher at the International Development Department, University of Birmingham.