Are you suffering from your messy web server config files? Do you have a craving for maintainability and flexibility, but worry about performance? This talk introduces a real migration story from nginx to H2O in a large-scale photo sharing service, illustrating how mruby scripting makes it easier to write and maintain configurations. We'll see real configuration examples, some issues we faced and the final result with some benchmarks. In addition, I'll show a lot of shiny new features and mrbgems added recently. You'd be surprised how advanced things can be done with H2O and mruby! In the talk, Kazuho Oku will also discuss the standardization of H2 extensions, QUIC, and how they are likely to affect web application development and deployment.