Implements a database-backed fixed-window rate limiter with configurable window size, max attempts, and ban duration. Uses PostgreSQL for shared state across instances, with atomic increment and ban expiry. The pattern is self-contained and can be extracted for any Node.js application needing distributed rate limiting without Redis.

Handles notification fan-out by claiming events with `UPDATE ... FROM ... SKIP LOCKED`, processing them per category with batch cursors, and writing results with `ON CONFLICT DO UPDATE`. This pattern ensures at-least-once delivery with minimal contention and is reusable for any event-driven system needing reliable, scalable fan-out over PostgreSQL.

Implements the `StorageModule` interface for local disk storage, with atomic writes via temporary files, path prefix generation, and automatic pruning of empty directories. The pattern demonstrates a clean abstraction for pluggable storage backends and can be reused as a template for implementing other storage targets (S3, Azure, etc.) with minimal adaptation.

Derives the ProseMirror editor schema directly from the markdown renderer's node types and marks, ensuring that any content produced by the visual editor can be serialized back to markdown without silent data loss. This pattern is critical for any WYSIWYG editor that must maintain round-trip fidelity with a source format, and the approach of deriving schema from renderer is non-obvious and highly reusable.

A LitElement custom element for rendering diagrams (Mermaid, PlantUML, etc.) with a static `definition` metadata object, shadow DOM, dark mode support via CSS custom properties, and content editing via a fenced code block. This component exemplifies the block system pattern used throughout Wiki.js: self-contained, declarative, and easily portable to other projects needing embeddable rich content components.