As an academic David has taught at the University of Florida, Eastern Oregon State College, Blue Mountain Community College, the University of Alaska, and San Francisco State University. David also taught as part of a teacher exchange with Japan. In Japan, on the northern island of Hokkeido, in the Akaigawa region, he taught in seven different schools. David also taught in several high schools across Alaska including high schools in Barrow and the Bethel region. David was awarded an Annenberg Fellowship to the Breadloaf School of English as a member of the Breadloaf Teacher Network. David left teaching in 1997 to begin a career in technology. 

In the technology space, David has worked for Remedy Corporation, Aurigin Systems, AvantGo, Satmetrix, TailWind, his own consulting business David Koehn Inc., Saba, Oracle, and D2L. David's use of technology for learning has been evident from the nascent days of the Internet to his current efforts at D2L. 

David's commitment to the arts is longstanding. In high school he attended the Pennsylvania Governor's School for the Arts and returned there later during college for two consecutive summers as an Assistant Teacher and Resident Assistant. Throughout college and graduate school David wrote and published widely. He had the good fortune of working with Jim Daniels, Debora Greger, William Logan, and Donald Justice. In the years to follow David would have the opportunity to study with many more poets, writers, and artists including Dean Young, C.D. Wright, Robert Pinsky, Robert Hass, Sharon Olds, Andrew Hudgins, Arthur Sze, Donald Revell, Rusty Morrison and many others. 

David has gone on to publish several books of poetry, Coil (a chapbook of poems), Tunic (a letterpress chapbook of translations of Catullus) and Twine (a full length collection of poems). David also edited Compendium about Donald Justice's thoughts on prosody. His next full-length book of poems, Scatterplot, is due for release in 2020.