During this time she was an active and outspoken member of the Ukrainian dissident movement. She continued publishing into the post-Soviet period, and in 2010, she published her first novel, Notes of a Ukrainian Madman, an account of the social and political upheaval in independent Ukraine, which immediately became a bestseller. Kostenko was born not far from the Chernobyl Zone, and in the 1990s she worked in the affected area on the preservation of cultural heritage. The disaster is a major preoccupation of her work.