Before being elected to the Assembly in 2014, Irwin worked as a systems engineer at Johns Hopkins University and Teledyne, then served as a two-term mayor and three-term city councilmember in Thousand Oaks.

[1] In 2014, Irwin successfully ran as a Democrat in the race to represent California's 44th State Assembly district, defeating Republican opponent Rob McCoy.

[9] Irwin has also been appointed to other significant roles including the Governor's Military Council,[10] and as co-chair of the National Conference of State Legislature’s Task Force on Cybersecurity.

[21] Irwin also secured $3 million to support local law enforcement efforts to recover firearms from individuals listed in the Armed and Prohibited Possessors System.

Irwin spearheaded efforts to collect personal protective equipment (PPE) for front line health care workers[26] and organized blood drives during a local shortage.

[33] Irwin also worked to protect the elderly from hospice fraud by prohibiting incentive payments, a problem highlighted by investigative journalism by the Los Angeles Times.

[34]  She partnered with County Clerks to make permanent Californian’s ability to request vital records (e.g. birth, marriage, death certificates) online, rather than visit offices in person.

[1] After her efforts to amend provisions of the California Consumer Privacy Act in 2019, which passed unanimously through the legislature and were signed by the governor,[37] she received criticism for possible conflicts of interest based on her husband's position as COO of Ring.