Backend System Design

Q: What is a Claude Code skill and how does the Backend System Design skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Backend System Design is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at https://claudskills.com/learn/what-is-skill-md/.

Category: Security · Sub-category: security-misc · Last updated: 2026-07-21

type:review

Produce a staff-grade backend system-design RFC for the active task: a 12-section design document (problem, requirements, architecture, data model and storage, API contract, caching, scaling and bottlenecks, reliability and SLOs, security, observability, rollout and migration, trade-offs) for a new service, endpoint, or backend feature, persisted as BACKEND_SYSTEM_DESIGN.md. Capability-routed, not stack-specific; composes with slo-define, performance-budget, api-contract-review, and release-plan rather than duplicating them. Use when a backend service or feature needs an architecture-level design before planning and slicing. Do not use to slice an already-designed change (use implementation-plan), to analyze blast radius (use impact-analysis), to review an API contract in isolation (use api-contract-review), to design the frontend surface (use frontend-system-design), or with no active task folder (run task-init first).

Security AStatic scan found no risk patternsHow grading works ›

From the source SKILL.md

Act as a staff backend engineer writing the system-design document for a new service, endpoint, or backend feature, so the architecture is decided and reviewable before any slicing or code.

What this skill does

Backend System Design is a community-contributed Claude Code skill in the security-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/backend-system-design/ and loads when your prompt matches the skill's trigger.

When to invoke it: Use when a backend service or feature needs an architecture-level design before planning and slicing. Do not use to slice an already-designed change (use implementation-plan), to analyze blast radius (use impact-analysis), to review an API contract in isolation (use api-contract-review), to design the frontend surface (use frontend-system-design), or with no active task folder (run task-init first).

Who uses this skill

The Backend System Design Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 156,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).

How to install

Free

Manual install (2 steps)

mkdir -p ~/.claude/skills/backend-system-design
curl -L https://claudskills.com/skills/backend-system-design/SKILL.md \
  -o ~/.claude/skills/backend-system-design/SKILL.md

Or just download SKILL.md directly and drop it into ~/.claude/skills/backend-system-design/. Claude Code auto-discovers it on next session.

Skills live at ~/.claude/skills/backend-system-design/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\backend-system-design\SKILL.md on Windows. See the full install guide for step-by-step instructions.

📱 Install from your phone or desktop Telegram

Open @claudskills_bot on Telegram, tap Open Desktop App, and the desktop app installs this skill for you. Or share the bot link with a colleague — they get the same one-tap install. Learn more →

Pro

One-click install via the desktop app

The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.

Pro

For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.

See pricing → Download desktop app

Frequently asked questions

How do I install the Backend System Design Claude Code skill?

Install via the ClaudSkills desktop app (one click) or copy SKILL.md from the source repository to ~/.claude/skills/backend-system-design/SKILL.md and restart Claude Code. Both flows are detailed at claudskills.com/install/.

What does the Backend System Design skill do?

Is this skill free to install?

Yes. ClaudSkills is an open registry — every skill keeps its source repository's license, and manual install via copy is free. ClaudSkills Pro ($9/mo, $79/yr, or $149 one-time) adds one-click install via the desktop app and a multi-signal Quality Score.

When should I use the Backend System Design skill?

Use Backend System Design when your Claude Code task falls under the Security category — specifically in the security misc area. Claude Code auto-discovers installed skills and invokes the right one based on the task description, so you can also ask Claude directly (e.g. "use Backend System Design" or describe the task and let Claude pick). Browse related skills at /category/security/.

What is a Claude Code skill and how does the Backend System Design skill fit in?

A Claude Code skill is a SKILL.md file that lives under ~/.claude/skills/<name>/ and tells the Claude Code CLI agent how to perform a specific task (instructions, prompts, allowed tools). Skills are auto-discovered at session start. Backend System Design is one of 67,000+ skills indexed in the open ClaudSkills catalog, classified under the Security category. Learn more at /learn/what-is-a-claude-skill/.

Attribution & license

Source: https://github.com/Mozurok/fhorja.dev/blob/HEAD/.claude/skills/backend-system-design/SKILL.md
License: MIT
Author: Mozurok
Website: https://fhorja.dev

Cite this skill

If you reference this skill in a blog post, paper, or documentation, you can cite it as:

APA

Mozurok. (2026). Backend System Design [Claude Code skill]. ClaudSkills. https://claudskills.com/skills/backend-system-design/

BibTeX

@misc{backend-system-design-2026,
  author    = {Mozurok},
  title     = {Backend System Design [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/backend-system-design/}
}

Embed this skill

Promote, attribute, or link this skill from your own README, blog post, or documentation. All three snippets are free to use — no sign-up, no API key. More distribution surfaces →

Badge

[![ClaudSkills](https://claudskills.com/badge/backend-system-design.svg)](https://claudskills.com/skills/backend-system-design/?utm_source=badge&utm_medium=readme&utm_campaign=skill_badge)

Security scan

Grade A · scanned 2026-07-21 — free static scan against the OWASP Agentic Skills Top 10.

No risk patterns were found in any of the ten OWASP-aligned categories. How grading works ›

✓ Prompt injection
✓ Data exfiltration
✓ Supply chain
✓ Reverse shell
✓ Credentials
✓ Execution
✓ Filesystem
✓ Persistence
✓ Obfuscation
✓ Network

Show this grade on your repo (click to copy):

[![Security: A](https://img.shields.io/badge/Security-A-2e7d32)](https://claudskills.com/skills/backend-system-design/#security)

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Browse all Security skills → Top 100 skills

Part of ClaudSkills — the open registry for Claude Skills & Claude Code Skills. · What's New · Install guide · About · llms.txt

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