Ernesto Tagwerker

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 ReplaceLINKS- Ernesto's LinkedIn- Ernesto's Bluesky- FastRuby.io- OmbuLabs- Ryan's Website- Brendan's X/Twitter- Brendan's BlueskySend us Fan Mail