poa attended cambridge university on a scholarship from singapore's public service commission (psc) and completed a degree in mathematics with first class honours. she met her future husband, tony tan lay thiam, while they were both students at cambridge. upon completing her degree, poa returned to serve in the singapore civil service and was appointed to the administrative service. she was first posted to the prime minister's office, where she served in the public service division and was involved in personnel policies within the civil service. she then moved to the ministry of finance, where she was the assistant director for indirect taxation.