During January 2026, Jan Kowalski enhanced participant filtering in the Solvro/backend-eventownik repository by updating backend queries to include participants with a 'block' type. Using TypeScript and database querying skills, Jan modified the system to ensure block-type participants are now accurately represented in segmentation, analytics, and admin workflows. This change improved data quality for reporting and downstream processing by expanding the coverage of participant queries. Jan verified that the updates maintained performance stability and did not introduce regressions in related query paths. The work demonstrated a focused approach to backend development, addressing a specific data handling requirement within the project.