[2] A Public Service Commission scholar, Poa graduated from the University of Cambridge in 1992 with a first-class honours degree in mathematics.

Poa attended the University of Cambridge on a scholarship from Singapore's Public Service Commission, completing a degree in Mathematics with first class honours.

[3] At Cambridge, she met her future husband, Tony Tan Lay Thiam, also a government scholar.

After four years, Poa left the civil service and joined the investment department of an insurance company as an analyst.

[6] In the 2011 general election, Poa along with team members, Sebastian Teo, Tony Tan, Nor Lella Mardiiiah and Mohamed Jeisilan Sivalingam contested in Chua Chu Kang GRC.

In June 2011, Poa was elected as the Secretary-General of the NSP by the Central Executive Council following the resignation of Goh Meng Seng.

[15] Poa, along with a team members, Tan Cheng Bock, Leong Mun Wai, Nadarajah Loganathan and Jeffrey Khoo contested in the 2020 Singaporean general election at West Coast GRC but failed to garner a majority against the incumbent People's Action Party team, but was awarded two seats under the Non-constituency Member of Parliament (NCMP) scheme.

In July 2023, Poa raised a private member's motion in Parliament calling for Group Representation Constituencies to be abolished.

[29] In August 2024, Poa raised another private member's motion in Parliament, calling for changes to how electoral boundaries are drawn.