Keynote: 365 Days Later: Moving From Java To RoR And How It Changed Everything
John Dewsnap • Philadelphia, PA • Keynote

Date: July 08, 2025
Published: not published
Announced: May 07, 2025

Last year at RailsConf Detroit, keynote speaker Irina Nasarova announced that Flexcar was launching on Rails that very day— in the middle of the conference. Now, one year later, I’m here to share the full story of how that transition unfolded, how things played out, and what life has been like for us after a full year on Ruby on Rails.

Flexcar made the bold decision to move from a Java-based architecture with 80 micro-services to a monolithic Ruby on Rails application in just four months. While this transition would have been aggressive to do in four months with an experienced Rails team, our team was brand new to RoR. This shift has had far-reaching effects—not just on our tech stack, but on our workflow, team dynamics, and company culture.

In this talk, I’ll take you through our journey, sharing lessons learned, challenges we overcame, and what I wish I had known before embarking on this path. We’ll dive into how the transition affected our development process, how we gained company-wide support, and the unexpected successes (and a few surprises) that came after the launch.

If you’re an engineering leader considering a similar move or a switch to Ruby on Rails, you’ll leave this session with:

- Insights into managing a successful tech stack migration and avoiding common pitfalls
- Strategies for securing buy-in from leadership, product, and support teams
- How the shift to Rails reshaped our team, processes, and products

Join me for a candid reflection on a year of change, growth, and lessons learned, and take away actionable tips to ensure your own transition is as smooth and successful as possible.

RailsConf 2025