Rajat Rajan

Full Stack Developer

HCLTech | Horsham, PA

Jan 2021 – Apr 2025

• Managed and supported over 300+ .NET applications across staging, UAT, and production, ensuring consistent uptime and deployment reliability.
• Monitored and installed 100+ SSL certificates on internal AWS ALB, Palo Alto firewall, and collaborated with cross-functional teams to renew certificates on external infrastructure including CloudFront and external ALBs, enhancing system security and trust compliance.
• Evaluated technical risk and ensured compliance for applications, reducing potential vulnerabilities and aligning with organizational security standards.
• Led the migration of 100+ legacy applications from Windows Server 2008 to 2016, increasing system performance, security, and compatibility.
• Performed spoof tests and successfully onboarded 200+ sites onto Load Balancers and CDN, resulting in faster content delivery and improved site reliability.
• Resolved critical issues in production .NET applications, leading to a 25% reduction in downtime incidents and strengthened stakeholder relationships.
• Executed infrastructure modernization by provisioning new servers, configuring AWS ILB/ELB, syncing data, managing DNS transitions, and implementing SSL/CDN setups—migrating 75+ apps with minimal disruption and enhanced availability.
• Developed scalable Java-based web applications using Spring Framework, integrating with AWS OpenSearch APIs to enable real-time data retrieval and update functionality for end users.
• Optimized SQL queries and stored procedures, reducing database query times by up to 40% and improving overall application performance.
• Designed and executed unit and integration test suites, achieving 95%+ test coverage, ensuring code reliability and maintainability.
• Implemented CI/CD pipelines using Jenkins, contributing to 20% faster deployment cycles and reducing release errors.
• Configured deployment environments across development and production stages, ensuring smooth rollouts with zero critical post-deployment issues.
• Documented functional and technical requirements, enabling cross-team clarity and reducing rework during development by 30%.