Install, configure, maintain, upgrade, and manage Oracle, MySQL, MariaDB, and Microsoft SQL Server databases across production and non-production environments. Continuously monitor database performance, availability, storage capacity, active sessions, system logs, and resource utilization to identify and resolve potential issues proactively. Evaluate SQL queries and execution plans, implement query optimization, indexing strategies, and database tuning to enhance overall system performance. Develop, execute, and verify database backup and recovery procedures, including periodic disaster recovery drills, to ensure compliance with established Recovery Point Objectives (RPO) and Recovery Time Objectives (RTO). Maintain and support database high availability, replication, clustering, disaster recovery mechanisms, and failover testing in accordance with platform-specific requirements. Implement and maintain database security measures, including access management, role-based permissions, least-privilege access, audit logging, security hardening, and regular patch updates. Troubleshoot database-related incidents, conduct root cause analysis, coordinate issue resolution, and implement preventive measures to minimize recurring problems. Automate routine database administration, monitoring, maintenance, housekeeping, and reporting activities using Bash scripting and other approved tools. Coordinate with application and infrastructure teams to support database deployments, schema modifications, data migration, system releases, and rollback procedures. Monitor database capacity and data growth, and manage archiving and retention processes in accordance with organizational policies and business requirements. Prepare and maintain technical documentation, database configuration records, standard operating procedures (SOPs), and operational reports.