Shipping is your heartbeat: Rails in the agentic era

In 2013, Fin's CTO wrote that shipping is your company's heartbeat — software only starts learning when it reaches customers. In the agentic era, that heartbeat has to get stronger, but it has not been plain sailing. As agents increased the amount of code moving through Fin, our test suites, deployment pipeline, and shipping process started to strain, slow down, and cost far more than we were comfortable with. This talk goes inside our Rails monolith (3M+ lines of code, 100k+ tests, P50 suite time around 3 minutes, merge-to-customers in under 10 minutes) to show how we got speed and safety pulling together again.