The generative AI tooling ecosystem has exploded over the past two years. What started as a handful of Python libraries has grown into a rich, opinionated landscape of frameworks spanning multiple languages, deployment targets, and philosophical bets. As a developer who has shipped production applications using all five of the frameworks covered in this article, Genkit, Vercel AI SDK, Mastra, LangChain, and Google ADK, I want to offer a practical, hands-on view of where each one excels, where each one falls short, and what I would reach for depending on the project I’m building.