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 Mentioned

Active 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 Lars

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On 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 Mentioned

• AWS 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

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On 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 Hilary Stohs-Krause, a Senior Software Engineer at Red Canary. They explore how engineering teams approach everyday performance work, from small Active Record optimizations to larger architectural decisions. Hilary shares insights from Red Canary's journey switching from React to Rails' native Hotwire stack, how her team tackled flaky test failures that were slowing down continuous deployments, and some strong opinions about custom linters.

🧰 Tools, Libraries, and Books Mentioned

• RuboCop – Enforces Ruby style and conventions, with support for custom cops.
• haml-lint – Linter for HAML templates to enforce consistent view code.
• ESLint – JavaScript linter used for maintaining consistent code quality, especially in React.
• HadoLint – Linter for Dockerfiles to catch common issues and enforce best practices.
• SitePrism – Page-object model DSL for Capybara to reduce flaky system tests.
• Sidekiq – Background job processor used in production Rails environments.
• Turbo – Part of the Hotwire stack for reactive updates without full-page reloads.
• Stimulus – Lightweight JavaScript framework for enhancing HTML with small interactions.
• Hotwire – A set of tools (Turbo + Stimulus) for building modern web apps without heavy JavaScript.
• Thinking in Bets – A book about better decision-making under uncertainty, by Annie Duke.

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On 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 Ryan Stawarz and Austin Story from Doximity, where Ruby on Rails has powered the core of their platform for over 15 years. The trio digs into how a single Rails monolith has evolved to support 100+ engineers and a mobile-first experience for millions of healthcare professionals. From front-end framework migrations to API architecture, they explore the real-world decisions required to keep a large Rails app resilient and fast-moving.

Ryan and Austin walk us through the team’s adoption of GraphQL, what led them to introduce GraphQL Federation, and how they balance speed with reliability when scaling APIs across domains. They talk about the tradeoffs of maintaining both GraphQL and REST, and how Doximity avoids N+1 query pitfalls using BatchLoader. The conversation also touches on the evolution of their front-end—from Backbone to Vue.js—and why Rails’ flexibility still gives them an edge.

Throughout the episode, they share pragmatic insights into debugging at scale, managing one-off data migrations, and determining when a service should live inside or outside the monolith. They also reflect on their use of tools like Packwerk, AnyCable, and Departure, and how a culture of trust, documentation, and lightweight planning helps Doximity move fast without breaking things.

🧰 Tools & Libraries Mentioned

- Ruby on Rails – The web framework powering Doximity’s monolith and many of their services.  

- GraphQL-Ruby – Ruby gem for building GraphQL APIs in Rails.  

- BatchLoader– Helps reduce N+1 queries in GraphQL.  

- Vue.js – Their chosen frontend framework for building single-page applications.  

- Packwerk – Helps enforce modular boundaries in their Rails monolith.  

- Departure – Used for safe database migrations on large datasets.  

- Thor – Used to run one-off CLI scripts with easier testability.  

- rake-ui – Internal tool for triggering Rake tasks via a web UI.  

- AnyCable – Go-based replacement for ActionCable to support realtime features at scale.  

- Docker – Powers consist

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On 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, Nadia Odunayo, founder and solo developer of The StoryGraph, joins us to share what it really takes to build and maintain a Rails application used by over four million readers across web and mobile.

We discuss lessons from launching a PWA, shifting to Turbo Native for cross-platform support, and navigating challenges like in-app purchases and data syncing between systems. Nadia also talks about the bold decision to move from Heroku to YugabyteDB to support growing workloads, and why she decided against hiring a team to manage it.

We also explore what it means to remain a solo developer by choice, the value of the Rails community, and why Ruby on Rails continues to be the framework that powers her entire business. 

Platforms & Distribution

• The StoryGraph – Nadia’s solo-built reading and book tracking platform 
• Apple App Store – The StoryGraph
• Google Play Store – StoryGraph 
• Progressive Web Apps (MDN) – Alternative mobile delivery method initially explored

Tools, Libraries & Services

• Ruby on Rails – The primary framework powering The StoryGraph 
• Turbo / Hotwire Native – Used to support mobile apps with shared Rails backend 
• Devise (GitHub) – Authentication library for Rails 
• Sidekiq – Background job processor 
• Makara (GitHub) – Database proxy for master/replica load splitting 
• Heroku – Former hosting platform for The StoryGraph 
• YugabyteDB – Postgres-compatible distributed database chosen for scaling 
• CTEs (Common Table Expressions) – Used for optimizing queries across distributed data
• Linear – Project management tool currently used by Nadia

Books

• Ruby Under a Microscope by Pat Shaughnessy – A deep dive into Ruby internals 

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On 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.

Jean Boussier, Senior Staff Engineer at Shopify and member of the Rails Core team, joins Robby to dig into the performance realities behind modern Rails apps.

They explore what it means to be IO-bound or CPU-bound, how Ruby’s Global VM Lock affects concurrency, and why "fast" is too vague to be useful. Jean explains why instrumentation is often the missing piece and shares thoughtful approaches to using background jobs with intention.

They also talk about gem dependencies. The gems in your `Gemfile` are not magic. If your app depends on them, you should understand them. You can read the code. You can patch it. You can make it your own.

This episode is a reminder that Rails is not a black box. It is a system you can study, shape, and improve. The more you learn how it works, the more confidently you can build with it.

🔗 References & Resources Mentioned

- 📖 Crafting Interpreters – A book Jean recommends for understanding how interpreters and Ruby internals work  

- 🧵 GVL Tools (Shopify gem) – A tool for measuring thread contention in Ruby apps  

- 📊 AppSignal – Monitoring platform that integrates with GVL instrumentation  

- 🚢 ShipIt Engine – Shopify’s open-source deployment tool  

- 🔒 Ruby’s Global VM Lock – Overview of what the GVL is and how it works  

- 🦄 Unicorn – A classic preforking Ruby web server  

- 🐆 Puma – A multi-threaded Ruby/Rack web server  

- 🔀 Pitchfork – Shopify’s fork of Unicorn, optimized for their infrastructure  

- ⚙️ ActiveRecord Async Queries – Jean’s Rails Core contribution for backgrounding slow queries  

- 🔗 GraphQL – Used at Shopify to structure and query API data

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On 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’, host Robby Russell (@planetargon) chats with Rosa Gutiérrez, Principal Programmer at 37signals, about the technical decisions behind Solid Queue - a database-backed job queue replacing Resque in their Rails apps.

Rosa dives into why her team built Solid Queue, how it improves reliability, visibility, and maintainability, and the challenges of migrating live apps like Hey during active development. Learn how they tackled recurring jobs, long-running tasks, and testing strategies, plus insights on system design, scaling, and the joy of deleting old code.

Topics:

• Why 37signals replaced Resque
• Building a job queue with ActiveJob + MySQL
• Transparent job states & using Mission Control as a dashboard
• Migrating with minimal impact
• Best practices for recurring and long-running jobs
• Recommended tools, testing gems, and dev books

Links:

• Rosa's migration script for scheduled jobs from Resque to Solid Queue
• Acidic Job
• Chaotic Job
• Rosa.codes
• Rosa’s videos on Ruby Events
• Rosa on the 37signals Dev blog
• Rosa on Github
• Rosa on LinkedIn
• Book Recommendation: Refactoring, Second Edition by Martin Fowler
  
  

#RubyOnRails #SolidQueue #BackgroundJobs #37signals #OnRailsPodcast

Send us a text

On 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.