• Designed and implemented backend components for three enterprise-scale internal systems, supporting high-volume data workflows across Finance, HR, and Infrastructure teams. • Optimized database queries and service logic, reducing average read latency by 40% and improving throughput for high-traffic endpoints. • Improved system resilience by implementing encryption, input validation, secure storage, and API-level protections, leading to zero breach incidents. • Strengthened system reliability by identifying and remediating critical vulnerabilities across services.