In the summer of 2020, Penn State's software engineering team was tasked with building a system for scheduling the testing of students, faculty, and staff for their arrival back to campus in the fall. In this HIPAA-compliant testing and scheduling system, Linkerd was installed because of its reputation for security and observability. As the team came to learn in February 2021, the #1 reason to have Linkerd is to troubleshoot performance issues. The engineering team sent out over 68,000 invites to those returning to campus to log into the system and schedule COVID tests upon return for the spring semester. The large load on the system highlighted where bottlenecks and bugs really existed. In this presentation, members of that team will discuss how they utilized Linkerd to secure, monitor, and troubleshoot the microservice-based system.