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.
Listen to this episode (1h 32m) or subscribe to On Rails in your podcast player.