[1] Choong has a vast experience as an accountant, auditor, tax agent and business consultant career.
He also serves as a Senior Independent Non-Executive Director on the board of Country View Bhd since 27 March 2002.
[4] Choong chose to participate in politics by joining People's Justice Party (PKR) at the age of 50 in 2007.
[6] He made his debut contesting the Tebrau parliamentary seat in the 2013 elections but had lost by 1,767 votes to the Malaysian Chinese Association (MCA) candidate.
On 28 February 2021, he was sacked from PKR to be an independent MP friendly to Prime Minister Muhyiddin Yassin's ruling Perikatan Nasional (PN) coalition together with Larry Sng.