Aleksandr Tereshchenko focused on infrastructure modernization and stability across the gptwrapper and sis-importer repositories. He attempted a Node.js 22 upgrade in Dockerfiles for gptwrapper, but after identifying compatibility issues, he restored Node.js 20 to maintain reliability. In sis-importer, Aleksandr consolidated NATS connectivity with explicit port handling and environment-based configuration, improving message queuing stability. He modernized the codebase by removing unused dependencies and updating the Redis client, while also upgrading the database migration framework to Umzug v3 with a rollback to ensure compatibility. His work demonstrated depth in backend development, containerization, and configuration management using JavaScript and Docker.