Ruby is All You Need

There is a common assumption in the industry that if you want to build serious AI-powered applications, you need to abandon your current stack and go Python. Spin up FastAPI, learn LangChain, containerise everything in separate services, and suddenly your Rails monolith starts to feel like something you should be ashamed of. Ruby — and Rails — already gives you what you need to build LLM powered features in production: background jobs, database persistence, a mature ORM, solid HTTP clients, and many years of patterns for building systems that actually work! You don't need to rewrite everything. You need to think differently about how you use what you already have. This series of articles are about that. Part 1: Why your tests are letting you down Most Rails projects I worked before reached for the same tools when it was time to write tests: RSpec, FactoryBot, some mocks, and the comfortable certainty that if you put the same input in, you get the same output out. This worked well for a