Prior to being elected to Parliament, Sim worked as a civil servant. From 1998 to 2000, she was an Assistant Director for Finance Policy and Planning at Singapore's Ministry of Health. From 2000 to 2003, she was an Assistant Director for Implementation Planning at the Ministry of Home Affairs. From 2003 to 2006, she became a Deputy Director for Trade at the Ministry of Trade and Industry. From 2007 to 2009, Sim was seconded to International Enterprise Singapore as the Regional Director. Based in Shanghai, Sim headed a team assisting Singapore-based companies with investment and sales in the East China region. From 2009 to 2011, she was the Director of the National Population Secretariat and she led efforts to restructure the Secretariat into the National Population and Talent Division.
Political career
At the 2011 general election, Sim was elected to Parliament as an MP for the Holland–Bukit Timah Group Representation Constituency. She was a member of the PAP's team in the GRC led by the Minister for Foreign Affairs, Vivian Balakrishnan, which defeated the team from the Singapore Democratic Party by 48,773 votes to 32,406. Since the election, she has represented the Bukit Timah ward within the constituency. Following the election, Sim was made the Senior Parliamentary Secretary at the Ministry of Education and the Ministry of Law. Subsequently, on 1 September 2013, Sim was made the Minister of State for Ministry of Education and Ministry of Communications and Information. In the General Election 2015, Sim was again a member of the PAP team contesting in the Holland – Bukit Timah GRC. The team, led by the Minister for Foreign Affairs, Vivian Balakrishnan, defeated the team from Singapore Democratic Party by 62,786 votes to 31,494 votes. On 28 September 2015, it was announced that Sim will be the Senior Minister of State for Ministry of Finance and Ministry of Culture, Community and Youth, effective 1 October 2015. With effect from 22 August 2016, Sim relinquished her appointment in MOF as Senior Minister of State and took on the role of Senior Minister of State at the Ministry for Trade and Industry. On 1 May 2018, Sim was appointed Senior Minister for State in the Ministry of Communications and Information, and relinquished her role in the Ministry of Trade and Industry.
