In Thinking while doing and doing while thinking, readers will learn about a framework that gives descriptions of Pedagogical Content Knowledge (PCK) to describe how teachers understanding of Design and Technology and PCK interact with one another to produce effective teaching of technology through design. The essence is to elucidate on the relationship between design and technology while also determining the essence of design and technology as a programme of study or subject in the school system as such bringing an understanding of the interdependence and complementary nature of technology and design in the Design & Technology as a subject as well as in STEM curriculum.