Mah began her first business when she was 11 by purchasing server space in bulk and selling fractions of the space for cheaper prices.[5] At the age of 13, she started her first internet company selling computer parts on eBay.[9][10]
In 2009, while at the University of California, Berkeley, Mah and her classmate Andy Su co-founded inDinero, a FinTech company providing accounting and financial software to businesses, and launched the firm's online dashboard a month after graduating from their computer science program.[9][11][12]
Following Mah's graduation, she and Su applied to Y Combinator's summer program,[13] and after presenting their idea formally to investors, they had 20 investors signed on.[14] By 2014, inDinero raised $8 million from angel investors,[8] and has raised more than $10 million by 2023.[6]
Mah has received recognition such as being named to Forbes 30 Under 30 under the enterprise technology category,[15] the Inc. Magazine 30 Under 30 list in 2012, and appeared on the August cover of Inc. Magazine in 2015.[16][17]
As of 2023, Mah has founded three start-ups,[14] including internshipIN an enterprise software as a service (SaaS) company[18] and Mahway, a venture builder with a portfolio of five companies that has attracted capital from Silicon Valley investors.[6]