Janssen & Spaans Engineering, Inc. is an Indianapolis based engineering consulting firm. Since 1976, JSE has been providing engineering excellence for government agencies, contractors and consultants for projects throughout Indiana, the United States, and abroad. The firm’s main office is located on the northeast side of Indianapolis with branch offices in Columbus, Indiana and Chicago, Illinois.

JSE specializes in providing transportation design solutions for complex bridge and road design projects. JSE's experienced professional staff of engineers is known for providing innovative and cost effective designs that benefit clients through reduced construction costs and improved construction efficiencies. JSE has earned a distinct reputation for providing unique design solutions for post-tensioned concrete structures. The firm’s ability to provide notable design solutions is attested by numerous national and local awards and by recognition in various national professional publications