Hwarang Yun served in various judicial roles from 2008 to 2025, handling a wide range of civil, criminal, labor, petition, and provisional remedy cases at the Supreme Court of Korea, Seoul Central District Court, and Seoul Southern District Court. In particular, he worked for two years in a labor-specialized division of the Seoul Central District Court, where he handled numerous labor-related cases and contributed to the drafting of case practice manuals and presentation papers on the subject. He also served as a senior judicial searcher of the joint criminal research group and as a chief judicial researcher at the Supreme Court for three years starting in 2018 and again for two years beginning in 2023, respectively, during which time he conducted in-depth research and adjudication on various civil and criminal cases, including those involving violations of the Unfair Competition Prevention and Trade Secret Protection Act and the Punishment of Tax Offenses Act and claims for damages against directors.