Worked on the solrbot/apache-_-solr repository to modernize and future-proof the Solr codebase by migrating core configuration and utility components from the deprecated MapSerializable API to MapWriter. This migration, completed as part of the SOLR-17600 initiative, improved memory efficiency and simplified ongoing maintenance by consolidating serialization logic. Using Java and leveraging backend development and API design skills, the developer removed all MapSerializable references, ensuring consistent API usage across the codebase. The work reduced deprecated API surface, enhanced compatibility for future updates, and established a more maintainable foundation for subsequent feature development within the Solr project’s backend infrastructure.