Developed an end-to-end LLM pipeline to extract and structure Cyber Threat Intelligence (CTI) from confidential PDF reports into STIX 2.1. Built and annotated a 4,738-example dataset and fine-tuned Mistral-7B and LLaMA 3.1 8B using QLoRA, 4-bit quantization, and PyTorch, achieving 0.7253 Macro F1. Integrated MITRE ATT&CK/MISP knowledge graphs, relation extraction, confidence scoring, and XAI for traceable CTI generation. Built an Angular + FastAPI application and deployed the solution on AWS (EC2, ECR, S3, CloudFront, CloudWatch) using Docker.