After graduating from Adelphi University, David Debin began his show business career as an Equity Stage Manager for touring musical comedies such as "Camelot" with Howard Keel and Jon Voigt, "Top Banana" with Milton Berle, "Guys and Dolls" with Dan Dailey, "Tovarich" with Eva Gabor and Jean Pierre Aumont, "Kiss Me Kate" with Patrice Munsell, and "How To Succeed In Business Without Really Trying," with Rudy Vallee. Later, he teamed with Oscar and Grammy winning composer, Paul Jabara, to write lyrics for the musical “Rachel Lilly Rosenblum and Don’t You Forget It" produced on Broadway by Ahmet Ertegun and Robert Stigwood.
His career in Hollywood began as a writer/producer for "The Dating Game" and "The Newlywed Game." He sold his first screenplay, “Dick Tracy,” to Universal, and his second, “Goldie and the Boxer,” to NBC. Under the banner of his own company he went on to produce “The Stockard Channing Show” for CBS; “Starmaker,” a miniseries starring Rock Hudson and Melanie Griffith for NBC; "A Gun in the House" with Sally Struthers, and "Silent Victory: The Kitty O'Neil Story" with Stockard Channing, both movies for CBS. Later, he served as writer-producer of the sitcom “Everything’s Relative,” starring Jason Alexander, for Columbia and CBS; and writer/producer of “The Heat,” starring Billy Campbell, for MGM and CBS. He also wrote episodes for TV shows such as “Hearts of the West,” and “Sweating Bullets.” At various times, he was a feature screenwriter under contract to Disney, Warner Brothers, MGM and Fox.
In 1992 Random House published his first novel, the Albie Marx Mystery, “Nice Guys Finish Dead.” Two subsequent Albie Marx novels, “The Big O” and “Murder Live At Five,” were published by Carroll & Graf. He also wrote three books of nonfiction, under the pseudonym of Smith and Doe, published by St. Martin’s Press. The first of them, "What Men Don't Want Women To Know" was an Amazon bestseller. He is a member of the Writer’s Guild of America, the Mystery Writers of America and the Author’s Guild.
With his business partner, Peter Brill, M.D., he co-founded The Third Age Foundation. The Third Age is defined as that period of life, which begins anywhere from ages 50-65, where people typically search for deeper meaning and fulfillment in their lives. The foundation has given seminars to thousands of people, along with workshops and support groups teaching the principles of living creatively in the Third Age. The program is called “Unfinished Business," and highlights seven steps which lead to passion, purpose and joy. A book entitled "Finding Your J Spot: JOY in Midlife and Beyond" was published by Third Age Books in 2005.
More recently, in 2013 he wrote and produced a comedy pilot for Mexican TV, "The Mexico City Angels," about a Mexican professional soccer team.
He has taught Creative Writing courses at Antioch University Santa Barbara and Santa Barbara City College.