[5] He later completed a second, joint-honours degree in computer science and psychology from the Open University in 2004, while working as a lawyer.
[15] After graduating from NUS with a Bachelor of Laws degree, Tan began his legal career in 1991 at Drew and Napier, a large Singaporean firm.
[2][17] Tan practiced litigation, and specialised in intellectual property, information technology, real estate, and shareholder oppression disputes.
[2] As president of the law society, he was known for his public outreach on legal issues,[28] such as the HDB's ban on cats,[29] the 2022 bar exam cheating scandal,[2] and Richard Branson's comments on the death penalty in Singapore.
[34] At a memorial service celebrating his life, Tan was said to be someone who "had very little ego", was a champion of the legal profession and who "cared for the less fortunate.
"[35] After his death, a collection of essays by Tan on the issues he cared about and commented on, was published in a book entitled, "If I were King of Singapore.