Irwan enlisted in the police force on 1 July 1995. He became an officer on 8 August 1996 and has since climbed the ranks from being the
assistant superintendent on 1 August 1998; acting
deputy superintendent on 1 January 2001; deputy superintendent on 1 July 2001; acting
superintendent on 1 June 2006; superintendent on 1 January 2008; acting
senior superintendent on 24 October 2009; and assistant commissioner on 10 May 2012. Another significant occasion in the history of the
ASEAN Chiefs of Police (ASEANAPOL) Secretariat occurred on 27 August 2019, when Irwan, the chairman, and
Abdul Hamid Bador, the
Inspector General of the
Royal Malaysia Police (RMP), paid an official visit to the secretariat's office. He would also attend the 39th ASEANAPOL conference in
Hanoi. The police headquarters in
Gadong held a ceremony to officially hand over the reins as police commissioner. On 4 March 2021, Jammy Shah Al-Islam signed the letter transferring responsibility to Irwan after successfully completing his service term. At a media conference held at the police headquarters, he highlighted that the administration takes the directive prohibiting
social isolation and holding any sort of group activity seriously amid the government's attempt in containing the
COVID-19 pandemic. During
President Jokowi's visit to the country on 13 January 2024, Irwan was among the first officials to welcome him. Later on 23 March, he presented the donations given to about 55 RBPF orphans during a ceremony held in the banquet hall of the police headquarters. On 15 June 2025, the
Borneo Bulletin announced that he would be relieved of his post and succeeded by
Sulaiman Alidin, who would serve as the acting police commissioner. == Personal life ==