As a Java engineer both by trade and by passion, I have had the opportunity to build and maintain many kinds of applications. My latest role has provided me the opportunity to maintain and optimize a large, high-traffic, legacy codebase. I have implemented several hot-path features like a feature-toggle system, automations around continuous delivery pipelines, and a custom blue-green deployment strategy to gradually introduce high-risk changes with minimal downtime. Additionally, I lead a 54-day cleanup effort of corrupt database indexes. The latest endeavors on the codebase include upgrading Hibernate from 4 to 5; Java from 8 to 21; and Spring Framework from 3 to 4 and then to 5. All while keeping up with the 3000 request-per-second load.