This is the story on how we moved to a Single Page Application using ClojureScript for our new payment checkout at Zimpler (a mobile payment company), the challenges we faced along the way, and how we setup the (optimal?) tooling for devs and designers alike. A tale of Figwheel, Amazon, re-frame, gulp, cache-busting, time-traveling debuggers, Honeybadgers, REPL-driven tests and broken iOS JIT compilers.