Prof Tan is an Associate Professor of the Department of Biochemistry at the National University of Singapore and the Chairman of the A*STAR Computational Resource Centre (A*CRC), and is currently the founding director of the National Supercomputing Centre (NSCC) Singapore. He is well known in the Bioinformatics field, having been a pioneering founder in Singapore (BIC, 1996) and in the Asia Pacific region (APBioNet, 1998), as well as in the field of advanced Internet networking (SINGAREN, 1997 and APAN, 1996).

As the inventor and founder of multilingual internationalised domain names (IDN) and a pioneer of the Internet, he was inducted into the inaugural Internet Hall of Fame by the Internet Society in 2012 together with the founding fathers of the Internet. Furthermore, he has spun off a number of companies, such as Technet Unit into Pacific Internet Inc in 1995.

He currently serves as Board Director of Keppel Data Centre REIT. He is also a Sub-Committee Focal Point of the ASEAN Committee on Science and Technology (COST), where he received the ASEAN Science and Technology Meritorious Service Award in 2008. He was also the winner of the Singapore Youth Award in 1994.