He was appointed Professor of Law at the Singapore Management University (SMU) in 2000, and made Chairman of the Department of Law at SMU's Lee Kong Chian School of Business in 2001.

In 2004, together with Tan Cheng Han, he was one of the first two legal academics in Singapore to be conferred the title of senior counsel.

He was appointed vice-president of the Court of Appeal with effect from 28 September 2017 following his predecessor Chao Hick Tin's retirement.

Phang retired as a Justice of the Court of Appeal on his 65th birthday on 15 December 2022.

He was subsequently appointed as a Senior Judge,[4] and, was, in November 2023, honoured by NUS for his contributions to the legal profession.