Active Agent with Justin Bowen

Jul 7, 2025

Justin Bowen, a Ruby developer with 17 years of experience, shares insights about Active Agent, his innovative Rails-native framework for integrating AI. He discusses challenges in shipping AI, emphasizing the importance of context and real-world testing. Bowen also critiques the hype around AI, comparing it to crypto trends. The conversation explores the balance between open-source sustainability and monetization, community involvement, and the evolution of Ruby in the AI landscape, while highlighting exciting projects like Osmo AI and the upcoming Ruby AI hackathon.

Ask episode

AI Snips

Chapters

Books

Transcript

Episode notes

ANECDOTE

Rails Origin Story

Justin Bowen started with Rails in 2007 and built computer vision projects for a decade before public talks.
He won a RubyConf ticket and gave a 2021 talk that launched his visibility in the community.

INSIGHT

Agents As Controllers

Active Agent models agents as abstract controllers that act like the C in MVC.
Prompts map to views and agents can access ActiveRecord and ActionView for deep Rails integration.

ADVICE

Validate Agents In CI

Test agents in staging against real models as part of CI to validate performance before deploying.
Record inputs (fingerprints/cassettes) so you can re-run evaluations when models or prompts change.

Get the Snipd Podcast app to discover more snips from this episode

Get the app

Seventeen-year Ruby veteran Justin Bowen joins hosts Valentino Stoll and Joe Leo to unveil Active Agent—a Rails-native framework that treats every agent like a controller and every prompt like a view, letting you weave LLMs, vector search, and business logic straight into MVC.

The crew also digs into the real-world mechanics of shipping AI: defining ground-truth datasets, replay-ready evaluation harnesses, and tight retry logic that keeps hallucinations out of production. You’ll hear a candid take on the current hype cycle (and its parallels to crypto), the challenges of long-term gem maintenance, and fresh ways to keep open-source sustainable—think GitHub Sponsors, corporate grants, and pro-tier gems.

What you’ll hear

Active Agent 101 – agents as abstract controllers, templated prompts as views
Testing in the wild – fingerprints, VCR cassettes & CI pipelines for non-deterministic code
Context is king – why ground truth matters when counting cows or parsing legal docs
OSS meets ROI – balancing passion projects with sustainable monetisation
Rails vs. Python/Next.js – reclaiming the one-person startup stack
Community fuel – Discords, hackathons, and the push for academic & corporate sponsorship

Mentioned In The Show:

Active Agent (GitHub) – Justin’s Rails-native, agent-oriented framework for building AI features.
Vercel AI SDK – TypeScript toolkit whose generative-UI ideas helped inspire Active Agent.
Maestra.ai – YC W24 startup offering AI transcription, dubbing, and hosted agent runtimes.
Matz's 2025 Ruby Kaigi AI Keynote
ONNX Runtime Ruby – Gem that runs ONNX models (CPU/GPU) from Ruby.
PGVector gem – Ruby bindings for PostgreSQL’s pgvector extension (embeddings storage).
Neighbor gem – k-NN / ANN vector search for Rails & Postgres—pairs nicely with PGVector.
Hugging Face JS – Run models in the browser with WebGPU and ONNX
Hugging Face Spaces – No-config platform for hosting ML demos; handy for sharing agent prototypes.
LangSmith (LangChain) – Evaluation & observability service discussed as a monetization model.
CrewAI (GitHub) – Python framework for orchestrating multi-agent “crews”; Joe’s current go-to.
Honeybadger – Rails-first error-monitoring SaaS—an inspiration for future Active Agent services.
Rising Impact – A Netflix anime special about a third-grader's journey to be the world's best golfer.
Osmo AI – Google-born startup using AI to digitise smell—cited in the show’s “AI hype” chat.
Ruby AI Builders Discord – Public Discord community for Rubyists building AI apps.