During September 2025, Dmitriy Maystrenko enhanced quiz integrity and UI consistency for the NationalSecurityAgency/skills-service repository. He refactored backend quiz logic using Java and Groovy to prevent correct answers from being shown on a user’s last failed attempt, ensuring graded results were withheld when the AlwaysShowCorrectAnswers flag was false. Dmitriy also updated the ApexCharts menu theme to align the user interface with the new quiz behavior, applying JavaScript for UI theming. He maintained quality by updating related tests to validate these changes. All modifications were delivered in a single, traceable commit, reflecting a focused and well-contained engineering effort.