What is the difference between HLD and LLD in this skill?

This skill focuses on high-cost architectural decisions, component boundaries, and system flows (HLD), while strictly excluding low-level implementation details like function signatures, specific algorithm pseudocode, or database DDL scripts (LLD).

How does it visualize system architecture?

The skill generates diagrams using Mermaid syntax, providing clear visualizations for system components, sequence flows, and state machines directly within the Markdown documentation.

Can it handle large features that span multiple services?

Absolutely. It includes a specific 1:N workflow where a large PRD can be split into multiple HLDs, managed by a centralized HLD Index document to ensure 100% requirement coverage.

Does it require a PRD and API Contract to function?

Yes, for the best results, it requires both to define the 'What/Why' and the 'Interface Contract.' This allows the skill to focus exclusively on the 'How' at an architectural level.

Does this skill help with technical debt?

Yes, it is ideal for planning refactoring or performance optimizations by providing a structured framework to document existing technical debt and propose architectural solutions.

HLD Design Architect

Name: HLD Design Architect
Author: TestAny-io

byTestAny-io

•

学習とドキュメンテーション

Generates comprehensive high-level technical design documentation based on PRDs and API contracts to bridge requirements and implementation.

HLD Design Architect (hld-writer) is a specialized Claude Code skill that streamlines the creation of high-quality High-Level Design (HLD) documents. It acts as an architectural bridge, translating product requirements and interface contracts into concrete technical strategies without overstepping into low-level implementation details. The skill features a rigorous evidence-based workflow that scans existing project documentation to prevent guesswork, ensuring all design decisions are aligned with current technology stacks. It is particularly effective for complex projects, offering automated requirement traceability, architectural visualization via Mermaid, and smart indexing for large features that require multiple design documents.

主な機能

01Support for 1:N splitting of large PRDs into multiple managed HLD documents

02Evidence-based context gathering through automated project document scanning

03Traceability matrix generation to map PRD requirements to HLD design sections

04Automated boundary enforcement to keep HLDs focused on architecture rather than implementation

05Architectural visualization using Mermaid for system flows and component boundaries

066 GitHub stars

ユースケース

01Coordinating technical design across multiple teams for large-scale product initiatives

02Planning technical refactoring or system optimizations while maintaining existing contracts

03Defining the technical architecture for a new feature after PRD and API contracts are finalized

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add testany-io/testany-agent-skills hld-writer

For use in Claude.ai and ChatGPT

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