Ernesto Tagwerker (FastRuby.io / OmbuLabs) returns to talk through how AI is reshaping both sides of his business — speeding up Rails upgrades while simultaneously eating into revenue, and opening a new lane in AI strategy consulting for non-technical businesses. The group digs into the messiness of AI-generated tests, mutation testing, and how to know when your tests are actually testing anything.

  01:00 FastRuby's Open Source Claude Skill for Rails Upgrades
  03:30 How AI Has Eroded (and Grown) FastRuby's Revenue
  07:00 Engineering as Marketing — Why They Open Sourced the Playbook
  10:00 The Tooling Isn't the Problem — Engineering Culture Is
  12:30 Using Claude to Write Contract Tests and Improve Coverage
  15:30 The Problem with AI-Generated Tests
  17:00 Mutation Testing Explained
  19:00 Classicist vs. Mockist — Where Claude Gets It Wrong
  23:00 Playwright for Acceptance Testing in the Development Loop
  26:00 Who Watches the Watcher?
  28:00 Staff Augmentation and AI Strategy at OmbuLabs
  31:00 Working with Non-Technical Businesses in Philadelphia
  33:30 Engagement Sizes — AI Discovery vs. Rails Upgrade Projects
  35:30 CRM Summaries and One-on-One Prep with AI
  38:30 Observability and Guardrails — How Do You Know It's Working?
  43:00 LLM as Judge
  45:00 Event Scraping — AI Makes Scrapers More Maintainable
  50:00 Ryan's Universal Scraper — Using AI to Heal, Not Replace

LINKS

- Ernesto's LinkedIn

- Ernesto's Bluesky

- FastRuby.io

- OmbuLabs

- Ryan's Website

- Brendan's X/Twitter

- Brendan's Bluesky

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