On Rails

In this episode of On Rails, Robby is joined by Alexander Stathis, a Principal Software Engineer at AngelList, where Rails powers complex investment, accounting, and banking business logic across a modular monolith structure. They explore how AngelList maintains conceptual boundaries in their codebase, uses gradual typing to influence their Ruby style away from Rails “magic,” and why they’ve adopted multiple async job solutions for different types of work rather than seeking a one-size-fits-all approach. Alex shares insights on consolidating microservices back into their monolith, creating the Boba gem to extend type generation capabilities, using production data subsetting tools for local development, and successfully onboarding engineers without Rails experience in under a month while staying current on Ruby 3.4 and Rails 7.2.Tools & Libraries MentionedActive Job – Framework-agnostic job API built into Rails.ASDF – Tool version manager.Boba – AngelList’s Sorbet compiler extension.Delayed Job – Database-backed job processor.FactoryBot – Test data builder.GoodJob – Postgres-backed Active Job processor.GraphQL Batch Loader – Batching utility for GraphQL.GraphQL Ruby – Ruby GraphQL implementation.Linear – Issue tracking tool.Money – currency handling library.Packwerk – Shopify’s modular boundary enforcement tool.Paperclip – Legacy file attachment gem for Rails (deprecated).RSpec – Ruby testing framework.Sidekiq – Redis-backed job framework.Solid Queue – Rails 8 Active Job adapter.Sorbet – Gradual static type checker for Ruby.State Machines – Finite state machine support.Tapioca – Sorbet RBI file generator.Temporal – Workflow orchestration system.Tonic – De-identified datasets platform.Will LarsSend us a textOn Rails is a podcast focused on real-world technical decision-making, exploring how teams are scaling, architecting, and solving complex challenges with Rails. On Rails is brought to you by The Rails Foundation, and hosted by Robby Russell of Planet Argon, a consultancy that helps teams modernize their Ruby on Rails applications.

In this episode of On Rails, Robby is joined by Florent Beaurain, a longtime Rails engineer at Doctolib, home to one of the largest Rails monoliths in Europe with over 3 million lines of code and 400+ engineers. They explore how Doctolib’s team tackled massive test suite performance issues, including cutting one engine’s test time from seven minutes to under one minute. Florent shares insights from managing 84,000 tests, scaling across 10 PostgreSQL databases, and maintaining Rails upgrades across a fast-moving organization using systematic approaches like dual-boot deployments and careful backporting strategies.  Tools & Libraries MentionedAWS Aurora (PostgreSQL) – Production database platform, scaled to 10+ writers and 15+ readers.Capybara – End-to-end testing of UI flows in the monolith.Capybara Lockstep –JavaScript sync layer reducing flakiness in React-driven feature specs.Datadog – Application performance monitoring for production systems.Docker – Local PostgreSQL and other data stores.FactoryBot – Identified as a major performance bottleneck in large test suites.factory_fixtures – Shopify gem extending fixtures with inline factory-style overrides. GitHub Copilot – Workflow automation and onboarding support.Heroku CI – Previously used for parallelized CI builds before moving to custom infrastructure.Jenkins – Original CI platform before scaling up to more powerful infrastructure.Minitest – Primary test framework, used throughout the monolith with some extensions.Packwerk – Used to modularize their monolith into engines with explicit boundaries and dependency declarations. PostgreSQL – Core relational database behind their production and local environments.React – Primary frontend framework, integrated into the Rails monolith via a single-page app architecture. Ruby on Rails – The framework behind Doctolib’s 3-million-line monolith and most of their core product infrastructure.safe-pg-migrations – Tool to reduce downtime risks during large-scale schema changes.Sentry – Error tracking and Send us a textOn Rails is a podcast focused on real-world technical decision-making, exploring how teams are scaling, architecting, and solving complex challenges with Rails. On Rails is brought to you by The Rails Foundation, and hosted by Robby Russell of Planet Argon, a consultancy that helps teams modernize their Ruby on Rails applications.

Hilary Stohs-Krause, a Senior Software Engineer at Red Canary, discusses her journey in the Ruby on Rails community and the nurturing culture for junior developers. She shares insights on optimizing performance through small decisions and enhancing user experience, particularly with a cat database project. Hilary delves into the challenges of flaky tests and the transition from React to Rails' Hotwire stack. She emphasizes the importance of coding standards and the impact of effective monitoring systems on engineering culture.

Ryan Stawarz and Austin Story, both Rails engineers at Doximity since 2016, share insights into their journey with Ruby on Rails and GraphQL. They discuss how Doximity evolved a monolithic Rails app to support over 100 engineers and millions of healthcare professionals. Key topics include the integration of GraphQL for mobile optimization, performance challenges, and the use of BatchLoader to handle data efficiently. They highlight the balance between GraphQL and REST, the evolution of front-end technologies, and emphasize a culture of trust to enhance team dynamics.

Nadia Odunayo, founder and solo developer of The StoryGraph, shares insights from running a book-tracking platform with over 4 million users. She discusses the journey from Heroku to YugabyteDB for scaling, and the technical challenges of in-app purchases across multiple platforms. Nadia emphasizes the significance of user feedback while developing mobile apps with Turbo and the hurdles of app discoverability in a competitive landscape. Through her experience, she highlights the value of the Rails community and what it means to be a solo developer by choice.

Jean Boussier, Senior Staff Engineer at Shopify and a key member of the Rails Core team, dives into the intricacies of Rails performance. He explains the distinction between IO-bound and CPU-bound issues and sheds light on Ruby’s Global VM Lock and its concurrency implications. Jean emphasizes the importance of understanding gem dependencies rather than treating them as magic. He shares insightful perspectives on background jobs and performance optimization, advocating for deeper engagement with Rails to enhance development productivity.

Rosa Gutiérrez, Principal Programmer at 37signals, shares her expertise on the development of Solid Queue, a new job management solution in Ruby on Rails. She discusses the decision to replace Resque, emphasizing improved reliability and maintainability. Rosa reveals the challenges faced during the migration of live apps like Hey, including strategies for managing long-running tasks and debugging failures. The conversation also touches on the joy of deleting old code, job scheduling complexities, and her favorite software reads that influence coding practices.