Practicing functional programming inside a Fortune 100 enterprise can feel like flying the Starship Enterprise through asteroid fields of legacy code and bureaucracy. This talk shares hard-earned lessons from the Information Engineering team at JPMorganChase, which runs a production Scala codebase powering a novel metadata platform. We'll explore the political, cultural, and technical friction of pushing functional programming in a Java and Python dominated environment. We'll introduce the domain we work in, the techniques that have worked (and those that haven't), the compromises we've made, and why - despite it all - we still think it's worth it. If you've never tried to run cats-effect in a place where Spring Boot is king, add this talk to your battle log.