Denys Kovalenko is a judge of the High Anti-Corruption Court. In 2006–2007, he worked as a court clerk at the Kharkiv Regional Court of Appeal, and in 2007–2010 he held inspector and managerial positions in the legal department of the Specialized State Tax Inspectorate for Large Taxpayers in Kharkiv. From 2010 to 2013, he headed the contract and legal department of the legal directorate of Zoloti Vorota JSCB, and since 2011 he has been engaged in legal practice as an attorney. In June 2013, he was appointed a judge of the Rubizhne City Court of Luhansk Region, and in 2022 he was seconded to the Kolomyia City-District Court of Ivano-Frankivsk Region. At the same time, he taught at the Volodymyr Dahl East Ukrainian National University and King Danylo University.