This course provides a comprehensive, hands-on introduction to Jellyfish, Cogito Group’s integrated platform for Public Key Infrastructure (PKI) and Certificate Lifecycle Management Software (CLMS). Designed for technical operators, security engineers, and platform administrators, the course bridges foundational PKI concepts with practical, real-world Jellyfish deployment and operation. Across four days, participants are guided from Conceptual Understanding to Installation, Configuration, Automation, and Troubleshooting of Jellyfish in a production-style environment. The course covers Jellyfish core components including the CLMS, Leviathan Certificate Authority (CA), and the Token/Card Management System (CMS), and explains how the modular services are composed using modern microservice architecture.