Alex Choi received a Diploma in Design with distinction in 1991 and Degree in Interior Design in 1994 from the Hong Kong Polytechnic University. During his studies, he was awarded Taoho Design Scholarship & the Cathy Pacific Travelling Scholarship to London. In London, he worked for Rick Mather Architects and was one of the key interior designers for the Keble College project in Norwich.

After graduation in 1994, he joined Foster Asia which is the architectural firm that involved in designing the Hong Kong & Shanghai Bank headquarter & Hong Kong International Airport at Chek Lap Kok. He participated in the final stages of the fitting-out part of Hong Kong International Airport and MTR Airport Railway projects for two years. After the completion of Hong Kong airport projects, he was appointed as the leading designer of MTR station improvement program. He was responsible for the project from design inception to mock-up construction. He was one of the key liaison designers with the MTR Corporation. In 1997, he left Foster Asia and established ACD (formerly known as ALEXCHOI design & Partners Ltd.).