KAITO (Kubernetes AI Toolchain Operator) is a production-grade Kubernetes operator that automates the full lifecycle of large language model (LLM) deployments. It reconciles custom resources—Workspace, InferenceSet, RAGEngine, MultiRoleInference, and ModelMirror—to provision GPU nodes, download or stream model weights from HuggingFace or Azure Blob, run inference servers (vLLM or HuggingFace Transformers), perform fine-tuning (LoRA/QLoRA), and manage RAG pipelines with vector stores (FAISS/Qdrant) and output guardrails. The operator supports multi-cloud node provisioning (Azure GPU provisioner, Karpenter, BYO) and features like prefill-decode disaggregation, model mirroring, and benchmark metrics collection. The system architecture is a collection of Go controllers using controller-runtime, with admission webhooks for CRD validation and a set of Python services for inference, tuning, and RAG. Key entry points: cmd/workspace/main.go (workspace controller), cmd/ragengine/main.go (RAG engine controller), presets/workspace/inference/vllm/inference_api.py (vLLM inference service), and presets/ragengine/main.py (RAG FastAPI service). Data flows: user creates a Workspace CR → controller creates NodeClaims, provisions GPU nodes, downloads/streams model weights → creates StatefulSet with inference service → exposes Service. For RAG: user creates RAGEngine CR → controller deploys vector store and inference service → user indexes documents via API → chat completions with retrieval augmentation. Notable engineering patterns include a plugin-based model registry (KaitoModelRegister), a generator pattern (WorkspaceGeneratorContext with chainable manifest modifiers), an abstract NodeProvisioner interface with multiple implementations, and a hot-reloadable guardrails system with Prometheus metrics. The codebase has extensive test coverage: unit tests with mock clients, integration tests for controllers, and end-to-end tests using Ginkgo that validate real cluster behavior. The project is actively maintained with frequent commits, CI/CD workflows, and versioned documentation.