Implements a pluggable adapter pattern for integrating multiple external game databases. Each source (VNDB, Bangumi, Hikarinagi, etc.) implements a standard interface (fetchById, searchByName, toDisplayFields), allowing the application to normalize and merge heterogeneous data. This pattern is reusable for any project that needs to aggregate data from multiple APIs, and the registry-based injection makes it easy to add or remove sources without modifying core logic.

A standalone async segmented download engine with cancellation via CancellationToken, stall timeout, chunk streaming, and background file sync. Supports resumable downloads, rate limiting, and progress reporting. Could be extracted as a reusable crate for any Rust application needing robust, concurrent download capabilities with minimal dependencies.

Implements a generic local TCP listener for OAuth authorization code flow with PKCE, supporting timeout, cancellation, and multiple concurrent attempts. This pattern is reusable for any desktop application needing OAuth authentication with a local callback server, and the design handles race conditions and port conflicts gracefully.

Implements per-source rate limiting with configurable minimum interval, exponential backoff on 429 responses, and event listeners for state changes. Reusable for any frontend or backend API client that needs to respect rate limits, and the design supports dynamic adjustment and monitoring of throttling state.