On Rails

Eddie Galindo is an engineering lead at Ascend and Kagen Hearn is a senior software engineer there, working on a Rails app that helps insurance agencies move and reconcile money.

Robby chats with Eddie and Kagen about why Ascend still runs one Rails monolith five years in, what changed when much larger customers started arriving, and how the team went about finding the real limits of their data ingestion pipeline. They also get into feature flags versus database configuration, and where AI tooling fits in when the software you ship moves money.

Links:
Ascend - https://www.useascend.com/

Send us Fan Mail

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.

Joanna Wang is a senior software engineer at Sixfold, where the team builds AI underwriting tools that help insurance companies gather data and assess risk. She came to Ruby on Rails after working across Java, Go, Python, and Node.

Robby and Joanna get into why the homegrown orchestration they built on state machines and callbacks turned brittle, what moving to Hatchet changed, and the tradeoffs of leaning on a gem that is no longer maintained. They also talk about what happened when the team went fully agentic, and why Rails magic is easier to understand when an agent can trace it for you.

Links:

Sixfold - https://www.sixfold.ai

Hatchet - https://github.com/hatchet-dev/hatchet

Send us Fan Mail

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 Aaron Patterson, better known online as Tenderlove, a senior staff engineer on Shopify’s Ruby infrastructure team and a longtime contributor to both Ruby and Rails Core. Aaron and Robby chat about how Ractors are finally bringing true multi-core parallelism to Ruby, the proposal Aaron has pitched to RubyGems.org for content addressable gems that could make bundle install dramatically faster, and the real reasons gems reach for native C extensions in the first place.

They also have a candid conversation about how Aaron actually uses AI day to day, from digging through unfamiliar code at Shopify's scale to building a JPEG encoder almost entirely with Claude, and why he still can't quite bring himself to trust it the way he trusts a longtime teammate.

Links

Tenderlove
Shopify
Ractors
RubyGems.org
FFI 

Send us Fan Mail

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 Bryce Harlan, a senior engineer at Phamily, the text-based chronic care management platform built by Jaan Health. Bryce has spent the last decade helping evolve Phamily's Ruby on Rails platform, which helps clinical practices coordinate between-visit care for patients with chronic conditions — sending and receiving roughly 100,000 Twilio SMS messages a day across hundreds of medical groups.

Bryce and Robby trade stories about a long-lived Rails app: the unconventional Rails 4-to-6 leap Phamily made during the spring 2020 surge in virtual care, the bespoke "Action Responders" pattern the team built to keep API serialization, authorization, and testing close to the model layer, and how an article from Judoscale on naming Sidekiq queues by their SLA reshaped how the team thinks about background work. They also dig into how Phamily is using Claude Code skills to give engineers "superpowers" on smaller features, and why Bryce now sees test suites as the closest thing to Peter Naur's idea of programming as theory building.

Links:
Phamily
Jaan Health
Programming as theory building
Judoscale blog: Planning Sidekiq Queues

Send us Fan Mail

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.

Robby is joined by Nikky Southerland, Lead Software Engineer at Shop-Ware — a cloud-based platform that helps independent automotive service shops run their businesses. Ruby on Rails has powered Shop-Ware since the first line of code was written back in 2013, and more than a decade later the codebase is still 90%+ Rails.

Robby talks with Nikky about what it actually takes to keep a mature Rails app moving with a team roughly half the size it used to be, including a frontend migration that's still in progress, the API decision they regretted almost immediately, and the LaunchDarkly kill switches that save them when a third-party integrator goes down.

Send us Fan Mail

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.

David Heinemeier Hansson, creator of Ruby on Rails and co-owner of 37signals⁩, joins Robby Russell the same week 37signals shipped Basecamp 5 to talk through the shift reshaping how software actually gets built today: why he reversed his "write every character by hand" stance, why he now considers taking AI seriously a professional obligation, and how cheap experimentation ("git reset and try again") is changing 37signals from the inside: designers and PMs working directly in code, and even the rigid six-week Shape Up cycle up for reconsideration. 

They also trace the history of Rails, including a backend so stable that a model file written today looks at home next to one from 2013, and take a peek at what's headed for Rails, from a Lexical-based editor ("Lexi") headed for ActionText to native passkeys and magic links. 

If you're curious where Rails is headed, have a listen.

Send us Fan Mail

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.

Tom Rossi, co-founder of Higher Pixels and the team behind Buzzsprout, joins Robby to talk about what it really looks like to stay "as Rails as possible", purely out of pragmatism. With over 472,000 podcasts on the platform and a team of fewer than ten people, Tom explains how sticking to vanilla Rails has been the foundation of Buzzsprout's ability to move fast, stay lean, and keep up with a rapidly evolving industry.

In this episode, Tom walks through Buzzsprout's migration from Paperclip to Active Storage (including what broke spectacularly in production), their recent shift from hand-rolled summary tables to ClickHouse for analytics, and how Hotwire made building the Buzzsprout mobile app surprisingly manageable. He also shares how Buzzsprout's real-world scale, including the monkey patching that resulted from it, led directly to contributions back upstream into Rails itself.

• Higher Pixels: https://www.higherpixels.com
• Buzzsprout: https://www.buzzsprout.com
• Buzzsprout Blog: https://www.buzzsprout.com/blog
• Tick (time tracking): https://www.tickspot.com
• Donor Tools: https://www.donortools.com
• StreamCare: https://www.streamcare.com
• Higher Pixels joins the Rails Foundation: https://rubyonrails.org/2025/2/18/higher-pixels-joins-foundation

Send us Fan Mail

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.

Jason Meller, founder of Kolide (acquired by 1Password in 2023) and now VP of Product at 1Password, joins Robby for a conversation about a career at the intersection of Rails, cybersecurity, and building.

They dig into why Rails has become one of the most token-efficient architectures for LLM-assisted development, and why that advantage matters as token costs increasingly shape what's worth building. 

Jason also shares what he's learned about keeping developer environments secure as agentic tools become part of everyday workflows, covering 1Password's open-source SCAM benchmark, how LLMs handle credentials when operating autonomously, and practical steps developers, founders, and engineering leaders can take to stay ahead of it.

Tools & Products

• 1Password (https://1password.com)
• Kolide (https://kolide.com)
• Cursor (https://cursor.com)
• Claude / Claude Opus by Anthropic (https://anthropic.com/claude)
• OpenAI Codex (https://openai.com)
• Lovable (https://lovable.dev)
• CrowdStrike (https://crowdstrike.com)
• GitLab (https://gitlab.com)
• Oh My Zsh (https://ohmyzsh.sh)
• Wiz (https://wiz.io)

Projects & Benchmarks

• SCAM Benchmark by 1Password (https://github.com/1Password/scam)
• OpenClaw (open-source agentic AI tool)
• Honest Security Manifesto (https://honest.security)
• 1Password Environments for Developers (https://developer.1password.com/docs/cli/secrets-environment-variables)
• The Rails Foundation (https://rubyonrails.org/foundation)

Books

• You Can Stop Stupid: Stopping Losses from Accidental and Malicious Actions by Ira Winkler & Tracy Celaya Brown (https://www.amazon.com/dp/1119566711)

Send us Fan Mail

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 Brian Scanlan, Senior Principal Engineer at Intercom, where a 15-year-old Rails monolith with millions of lines of code sits at the heart of the business.

Brian shares how Intercom's philosophy of being "technically conservative" has kept their engineering organization productive and focused on shipping product rather than managing infrastructure complexity, and on Intercom's all-in bet on Claude Code as their singular AI tool, now generating over 95% of daily code, with over 1,000 weekly users across the company including non-engineers in sales, marketing, and finance. Brian explains their approach to automated code review and PR approvals, how they built a Rails console MCP that lets Claude run production queries (with non-engineers as the top users), their layered plugin and skills architecture, and where AI still falls short in open-ended debugging, using the metaphor of commercial airline pilots who know when to disengage the autopilot.

Tools & Libraries Mentioned

• Claude Code — AI coding agent (mandated tool at Intercom) — https://docs.anthropic.com/en/docs/claude-code/overview
• Rotoscope — Shopify's tool for identifying test subsets — https://github.com/Shopify/rotoscope
• Honeycomb — Observability and tracing — https://www.honeycomb.io/
• RuboCop — Ruby linting and static analysis — https://rubocop.org/
• Snowflake — Cloud data warehouse — https://www.snowflake.com/
• Datadog — Monitoring and metrics — https://www.datadoghq.com/
• GitHub Dependabot — Automated dependency updates — https://github.com/dependabot
• Console1984 — Rails console audit trail gem — https://github.com/basecamp/console1984
•  Playwright — Browser automation (mentioned re: token consumption) — https://playwright.dev/

Books Mentioned

•  Designing Data-Intensive Applications by Martin Kleppmann 

Blog Posts Mentioned

•  Choose Boring Technology by Dan McKinley — https://mcfunley.com/choose-boring-technology

Send us Fan Mail

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 Simone Carletti, CTO of DNSimple, where Rails has sat at the core of a globally distributed DNS platform since the company launched in 2010. Simone walks through how DNSimple's infrastructure is organized across three primary languages - Ruby on Rails, Go, and Erlang - each chosen deliberately for the role it plays: Rails powering the main application and API, Go handling the zone server, and Erlang running their custom-built name servers. He explains why Rails has remained central even as the platform grew well beyond a typical web app, and what it takes to keep a long-lived codebase healthy with a lean team of around 15 engineers.

Tools & Libraries Mentioned

Sidekiq: Background job processing (enterprise edition).

RSpec: Testing framework.

Knapsack: Parallel test suite splitting.

Lograge: Structured JSON logging for Rails.

ViewComponent: Component-based view layer for Rails.

Hanami: Ruby web framework, used for portions of the DNSimple API.

PostgreSQL: Primary relational database.

ClickHouse: Analytics database for DNS query log processing.

Erlang/OTP: Runtime for DNSimple's custom name server (ErlyDNS).

Go: Language powering DNSimple's zone server.

Docker / Docker Compose: Used to run the full DNSimple infrastructure stack locally.

Cursor / Claude Code: AI coding tools adopted across the DNSimple team.

Terraform / Infrastructure as Code: Used to manage DNSimple's own domains and GitHub repositories.

Books Mentioned

Eloquent Ruby by Russ Olsen

Design Patterns (Gang of Four)

Send us Fan Mail

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.