The ecosystem of libraries, frameworks, and platforms that make building AI-powered applications easier. This includes orchestration frameworks (LangChain, LlamaIndex), inference servers (vLLM, llama.cpp), fine-tuning tools (Axolotl, Unsloth), evaluation frameworks (LMSYS, Braintrust), and full-stack platforms (Vercel AI SDK, Hugging Face). The tooling landscape changes monthly.
Why it matters
Raw model APIs are necessary but not sufficient. Developer tools bridge the gap between "I have an API key" and "I have a production application." The right tools can cut development time from months to days, while the wrong ones add complexity without value.