Behler previously served as the chief operating officer and deputy director for Carnegie Mellon University's Software Engineering Institute.

He has also held posts as president and chief operation officer of SRC Inc., as senior vice president and general manager at Mitre Corporation, and as the business area executive of Precision Engagement at Johns Hopkins University's Applied Physics Laboratory.

[1] On September 5, 2017, Behler was nominated by President Donald Trump to become Director, Operational Test and Evaluation at the United States Department of Defense.

His nomination was seen "as a nod to the increasingly critical and complex role software and cybersecurity plays in U.S. defense systems.

"[4] At his confirmation hearing, Behler said he would seek to speed up Department of Defense acquisition efforts and focus on software development and prototyping new weapons systems.