Cressler has been a faculty member in the Georgia Tech School of Electrical and Computer Engineering (ECE) faculty since 2002. He is currently the Schlumberger Chair Professor in Electronics and the Ken Byers Teaching Fellow in Science and Religion. 

A mainstay in the ECE microelectronics instructional program, Cressler has also introduced three new courses into three different areas of the Georgia Tech curriculum, ECE 6444: “Silicon-based Heterostructure Devices and Circuits;” CoE 3002: “Introduction to the Microelectronics and Nanotechnology Revolution;” and IAC 2002: “Science, Engineering, and Religion: An Interfaith Dialogue,” which is taught through the Ivan Allen College of Liberal Arts.  

Cressler has written books for each of these three courses. Silicon Earth (2016), now in its second edition and also translated into Chinese. Meant for a general audience, the book serves CoE 3002, which is intended for all majors, including both business and liberal arts students. Silicon-Germanium Heterojunction Bipolar Transistors (2003, with G. Niu) is the most widely cited textbook in this field and serves his graduate course, ECE 6444. In all of his courses during his 28+ year career, Cressler ends each of his classes, including IAC 2002, with a handed-out quotation and a sharing of a personal reflection relevant to his students’ lives. For this purpose, he compiled over 600 quotations and reflections in the book, Reinventing Teenagers (2004).

Cressler's career-long teaching effectiveness average is a 4.9, and he is a fully dedicated mentor to the students in his classes. On the research side, Cressler has mentored and graduated 60 Ph.D. students during his academic career (50 at Georgia Tech), and he and his team have published over 750 archival papers. The graduates of his research group have continued onto successful and meaningful careers in industry, academia, and government labs and agencies.

Cressler has received several high-level IEEE teaching and mentoring awards and has been presented with Georgia Tech’s top honors in undergraduate teaching and graduate student mentoring. In 2013, he was recognized with Georgia Tech's highest award for faculty, the Class of 1934 Distinguished Professor Award.