Advertise on podcast: 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machines and callbacks turned brittle, what moving to Hatchet changed, and the tradeoffs of leaning on a gem that is no longer maintained.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.comBuzzsprout: https://www.buzzsprout.comBuzzsprout Blog: https://www.buzzsprout.com/blogTick (time tracking): https://www.tickspot.comDonor Tools: https://www.donortools.comStreamCare: https://www.streamcare.comHigher Pixels joins the Rails Foundation: https://rubyonrails.org/2025/2/18/higher-pixels-joins-foundationSend 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/overviewRotoscope — Shopify's tool for identifying test subsets — https://github.com/Shopify/rotoscopeHoneycomb — 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/dependabotConsole1984 — 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.

In this episode of On Rails, Robby is joined by Jay Tennier, Engineering Manager at Rainforest QA, where he's spent over seven years working across a long-lived Rails monolith and supporting services. They explore how Rainforest maintains their platform with a small team, and the practical decisions that come with that reality. Jay shares lessons from pulling microservices back into the monolith, why they wrap third-party services in adapters, and how they push analytics work to BigQuery instead of straining their Rails database. The conversation covers testing philosophy including "wet tests" over DRY abstractions, using dry-monads for complex service flows, and how celebrating code deletion has become part of their engineering culture. Social + Web Presence LinkedIn: https://www.linkedin.com/in/jaytennier/ GitHub: https://github.com/jaytennie/  Twitter/X: https://x.com/jaytennier Bluesky: https://bsky.app/profile/jaytennier.bsky.social Company/Org Links Homepage: https://www.rainforestqa.com/ Tools & Libraries Mentioned Active Record: Rails ORM.   BigQuery: Hosted analytics warehouse.   Cube.js: API layer for querying analytics data.   DRY-Monads: Structured success/failure flow.   FactoryBot: Test data factories.   Grape: Ruby API framework. GoodJob: Background job processor.   Q Classic: DB-backed job queue.    Redash: SQL-based dashboards and reporting.   RSpec: Rails testing framework.   React: Front-end application framework.   Haml: Legacy templating engine.   Segment / Mixpanel: Event tracking pipelines. Books Mentioned Confident Ruby by Avdi Grimm   Exceptional Ruby by Avdi Grimm   Working Effectively with Legacy Code by Michael Feathers  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 Kayla Reopelle, a lead software engineer at New Relic, where she works on both the Ruby Agent and OpenTelemetry RubyGems. They explore what observability means for Rails developers—not just as a debugging tool, but as a way to build clearer, more reliable systems. Kayla explains OpenTelemetry's vendor-agnostic approach to instrumentation and shares practical ways to experiment with traces, metrics, and logs in both production and local development. GitHub: https://github.com/kaylareopelle  🧰 Tools & Libraries Mentioned ActiveSupport::Notifications: Rails’ pub/sub API used for instrumentation. AppSignal: Rails-friendly APM and error tracking. AWS X-Ray: Distributed tracing for AWS services. Datadog: Full-stack observability platform. Elastics Profiling Spec: Donated profiling format for OpenTelemetry. Grafana: Open-source dashboards and visualization. Honeybadger : Error monitoring for Ruby apps. Jaeger: Distributed tracing system (CNCF). New Relic Ruby Agent: APM agent for Ruby and Rails. ObservableGauge (OTel Metrics): Async gauge for snapshots like queue size. OpenTelemetry Collector: Pipeline for receiving and exporting telemetry data. OpenTelemetry Logger Bridge: Sends Ruby logger output to OTEL. OpenTelemetry Ruby: Vendor-agnostic telemetry for Ruby. OpenTelemetry Ruby SIG: Community group maintaining OTEL Ruby. Prometheus: Metrics collection and storage. Rack Middleware: Web middleware stack used in many Rails instrumentations. Rails Structured Logging / Event Reporter: Structured logs built into Rails. Semantic Logger: Structured logging for Ruby & Rails. Stripe Ruby Gem: Payments client used as an instrumentation analogy. UpDownCounter (OTel Metrics): Counter for tracking active jobs. 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 Miguel Conde and Peter Compernolle from Gusto, where they work on a "biolith"—two distinct Rails monoliths serving 600+ engineers. Peter leads the HIPAA-compliant benefits domain, while Miguel is extracting the time product from the main monolith. They explore how Gusto identifies boundaries, manages temporal data, handles eventual consistency, and navigates the trade-offs of GraphQL federation. 🧰 Tools & Libraries Mentioned ActiveAdmin: Admin UI for Rails. after_commit_everywhere: Run code after commits. Datadog: App and CI/CD observability. FactoryBot: Build test data. GraphQL: API layer for SPAs. Kafka: Event streaming backbone. Packwerk: Enforce boundaries in monoliths. PaperTrail: Model change auditing. React: Front-end framework. Sidekiq: Background job processing. Sorbet: Gradual Ruby types. TypeScript: Typed JavaScript. explicit_activerecord: Guard writes to models. Ruby Koans: Learn Ruby by practice. Cracking the Coding Interview: Interview prep book. Gusto Engineering Blog: Posts from Gusto engineers. 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 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 Larson – Staff Engineer – Book exploring technical leadership 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 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 visibility tool integrated into their release workflow.Webpack Dev Server – Used locally to support React development alongside the Rails app.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.