In August 2025, Ivan Seleznev focused on stabilizing the lets-plot-kotlin repository by addressing a critical bug in the core Kotlin API. He resolved a type inconsistency in RepelParameters across various geom functions, migrating parameter types from Float to Number to support more flexible input handling. This change reduced runtime errors and improved the robustness of the API for Kotlin-based data visualizations. Ivan’s work demonstrated a strong grasp of API development and type systems, ensuring that developers using lets-plot-kotlin benefit from a more consistent and reliable experience. The solution was implemented entirely in Kotlin, emphasizing maintainability and traceability.