Worked on the Solvro/backend-eventownik repository to enhance participant filtering by including those with a 'block' type, addressing a gap in data coverage for admin workflows and reporting. Using TypeScript for backend development and database querying, the update ensured that block-type participants are now accurately represented in segmentation and analytics processes. The implementation involved updating query logic to handle the new participant type, followed by thorough verification to maintain performance stability and prevent regressions. This work improved data accuracy for downstream processing, enabling more comprehensive participant management and reporting capabilities within the existing backend infrastructure. No bugs were reported or fixed.