Having worked extensively in the Shopify codebase, one of the largest rails apps in existence, I have experienced firsthand some of the downsides of working in monolithic codebases. These include painfully slow tests, new code causing unexpected repercussions due to dependencies across functional boundaries, and decreased developer productivity due to the need to understand the entire codebase to be effective in it. During this talk, I will discuss how to identify these symptoms and others that are tell-tale signs that the monolithic architecture is no longer serving you. Once identified, I will walk through the architecture and pros & cons of two alternative solutions, both of which I have implemented. About Kirsten Westeinde Kirsten Westeinde is a technology enthusiast and a lifelong learner. She is a Senior Software Developer at Shopify, where she builds technology to help entrepreneurs succeed in starting and running their businesses. She worked with Ruby on Rails for ~5 years, but has recently switched over to working in Go. She is passionate about building diverse teams, mentoring & teaching, and gaining new perspectives through travel & cross-cultural communication.