Chili3D is a browser-based parametric 3D CAD application built as a modular monorepo. It provides a full-featured modeling environment including 2D sketching with constraint solving, 3D feature-based operations (extrude, revolve, sweep, boolean, fillet/chamfer), and an AI assistant for conversational design. The geometry kernel is powered by OpenCascade compiled to WebAssembly, with Three.js handling rendering. The application is assembled via a builder pattern (AppBuilder) that composes optional modules (WASM kernel, parametric engine, Three.js viewport, UI framework, AI assistant, IndexedDB storage). The architecture is centered around a robust command pattern with @command decorators, MultistepCommand for wizard-like workflows, and a Transaction system for undo/redo. The parametric modeling engine is particularly sophisticated, employing geometric fingerprinting and history completion algorithms to maintain stable identities for faces and edges across parametric rebuilds. The AI assistant integrates deeply with the application, providing tools for reading document state, executing commands, and running parametric programs via LLM providers (Anthropic, OpenAI). The codebase demonstrates high craftsmanship in its foundation layer (Observable, Binding, PubSub, Result), math library (XYZ, Matrix4, Quaternion), and serialization framework. These components are cleanly abstracted and could be extracted for use in other projects. The plugin system and snap infrastructure are also well-designed. The project is actively maintained with a recent commit history and extensive test coverage. However, the project carries medium technical drift risk. It depends on precompiled WebAssembly binaries (OpenCascade, Garlic constraint solver) which require a complex build pipeline to regenerate. It uses a non-standard test framework (@rstest/core) and is on a beta version of TypeScript (6.0). The AGPL-3.0 license and single-author bus factor are additional considerations. Despite these risks, the engineering quality is strong, making it a valuable reference for anyone building complex web-based design tools or parametric modeling systems.