Denis grew up in the Bay Area and has taught in Waldorf schools for the past 39 years. He received his Waldorf Teacher Certificate and BA in Waldorf Education from Rudolf Steiner College in 1981. Denis was the founding teacher of Portland Waldorf School, where he brought his first class through the grades beginning in 1982. He began teaching at Sacramento Waldorf School in 1990, leading three lower school classes through the grades. Denis also taught mathematics for six years in the Sacramento Waldorf High School. Additionally, he was an adjunct faculty member for many years in the summer Teacher Education Program at Rudolf Steiner College.

Denis has three grown children of his own, all of whom are Waldorf graduates. His wife, Amber, is also a class teacher in Sacramento. His special joys are paragliding, rock climbing, music, camping, and traveling.