PyCaret 4.0 is a full-stack MLOps platform combining a low-code Python AutoML engine, a FastAPI control plane server, and a React web UI into a single deployable system. The engine provides OOP Experiment classes for classification, regression, clustering, anomaly detection, and time series, with native sklearn pipeline implementations and typed result dataclasses. The server adds multi-user workspace management, experiment tracking, model registry, deployment serving, drift monitoring, LLM-powered advisory copilots, scheduling, webhooks, and audit logging. The React frontend offers a rich SPA with real-time event streaming, interactive plots (Plotly), and data-driven forms generated from engine introspection. The architecture is well-structured with protocol-based abstractions for storage (local-fs/S3), data sources (CSV/Postgres), LLM providers (Anthropic/OpenAI/fake), and notebook backends. This is primarily an application (ML platform) but has strong data/research characteristics due to the engine's statistical analyses, dataset profiling, and time-series utilities. The codebase is under active development with a systematic migration from legacy functional APIs to the new OOP architecture, and many components are genuinely reusable.