Overview

In the presentation titled "2,000 Engineers, 2 Million Lines of Code: The History of a Rails Monolith," Cristian Planas, a Senior Staff Engineer at Zendesk, shares insights from his decade-long experience working with a Rails-based monolithic application at Zendesk. The talk reflects on the evolution of Ruby on Rails within the company over 15 years, addressing how to successfully scale a tech stack as a startup grows to a leading business.

Key Points

• Rails as a Foundation:

  • Zendesk was founded on Ruby on Rails and continues to utilize it as a core component of its technology stack.
    
  • The presentation draws parallels between the narrative of Romeo and Juliet and the evolution of the Rails community, emphasizing the drama and dynamics within the community over the years.
    

• Evolution of Monoliths:

  • The talk explores the changing perceptions of monoliths in tech, from being perceived negatively to a trend towards appreciation again.
    
  • Planas discusses his experiences with continuous optimization and the transition from a monolithic architecture to one including microservices and event-driven patterns, adapting as the company acquired new services and technologies.
    

• Technology Stacks and New Language Adoption:

  • As Zendesk has evolved, the company has developed a 'tech menu' for adopting new technologies, balancing the strong Ruby on Rails base with other languages like Java and Scala for specific services.
    
  • Much of the technology adoption at Zendesk has come from acquisitions, which introduce new languages and paradigms into the existing infrastructure.
    

• Testing Strategies:

  • Testing is heavily emphasized within the organization, with over 55,000 tests run every time changes are made, ensuring code reliability as the application grows.
    
  • The transition to automated tests and the continuous integration processes are key to maintaining healthy software delivery practices.
    

• Challenges of Scaling and Upgrading:

  • Planas highlights the difficulties faced during upgrades of the Rails framework, sharing anecdotes about the evolution of the codebase and the need to eliminate legacy practices such as extensive metaprogramming.
  • The complex interdependencies within a large legacy codebase often lead to significant issues during upgrades, illustrating the importance of proactive maintenance and clear ownership of code segments.
    

Conclusion

The talk concludes with reflections on the importance of adapting to change, learning from the past, and fostering a collaborative community within software engineering to keep pace with evolving technologies. Cristian Planas emphasizes that while building on a legacy codebase offers challenges, it also enriches the experience of engineers as they devise solutions to complex problems in a dynamic industry.