Miguel Conde & Peter Compernolle: Inside Gusto’s Rails Biolith
Show notes
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.
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.
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