Ehsan Aghaei is a Senior LLM Research Scientist at Cisco, where he drives innovation in applied artificial intelligence for cybersecurity within Cisco AI Defense. He specializes in the design and advancement of large language models and intelligent systems for AI validation, domain-specific language modeling, advanced model tuning, and agentic AI—enhancing Cisco’s capabilities in robust, explainable, and resilient AI-driven cybersecurity automation. Ehsan’s work bridges foundational research and applied engineering, enabling next-generation AI systems that advance threat reasoning, vulnerability assessment, and autonomous cyber defense at scale. Prior to joining Cisco, Ehsan was a Postdoctoral Fellow at Carnegie Mellon University’s School of Computer Science, where he contributed to several prestigious and high-impact national research programs in collaboration with DARPA, NASA JPL, NSF, ONR, ARO, and PNNL. His efforts focused on AI-driven vulnerability analysis, semantic modeling for cyber threat intelligence, attack-path analysis, and the development of intelligent deception and adaptive defense systems leveraging natural language understanding. Ehsan has authored numerous peer-reviewed publications, holds multiple patents, and has open-sourced several AI models advancing the intersection of large language models and cybersecurity innovation.