Ryan Sherlock

Ryan Sherlock

Senior Director of Engineering, Fin

Ryan Sherlock is Senior Director of Engineering at Fin, leading infrastructure and core technology. He works on reliability, developer productivity, and the three-million-line Rails monolith that powers Fin at scale.

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. I’ll cover the Ruby, Rails, CI, orchestration, observability, rollback, and automated AI review guardrails that got us to a better place than where we started.