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System design planner
Describe what you are building. Get an architecture choice with diagrams and the trade-offs behind it.
System design planner is a free AI skill for the job "Build and ship software". Give the instructions to an AI assistant that supports the required files and tools, then review its output.
Free · No account · MIT licence · Made by Alireza Rezvani · Level: advanced · Thinking: high
Made by Alireza Rezvani. See the original on GitHub; we copied it as it is, with its licence.
What it does
Pick an architecture before you build it, with a diagram and a clear record of what you give up for each choice. You get a recommendation on monolith or microservices, which database fits, and how the system should grow, so the decision is written down and not guessed. The skill works through decision flows. For databases it asks about data shape, scale and consistency needs. For structure it weighs team size and traffic against complexity. Optional scripts can scan a project folder, draw the architecture as a Mermaid diagram, and flag tangled or circular dependencies. Each recommendation lists the trade-offs, so you can defend the call to your team. The scripts need Python.
You give it
- A description of what you are building
- Expected users, traffic and team size
- Your project folder (optional)
- Constraints such as budget or cloud provider (optional)
- Codebase (optional)
You get
- A recommended architecture
- A diagram in Mermaid form
- A dependency check with problems flagged
- A trade-off summary for each choice
Use it when
- You are starting a new product and must choose between a monolith and services.
- You need to pick a database and want the reasons laid out.
- You inherited a codebase and want a diagram of how it really fits together.
- Your app is slowing under load and you need a plan to scale.
- You must explain an architecture choice to your team or manager.
How to use it
- Add it to your AI once: download it and add the folder to Claude, ChatGPT or Codex as a skill.
- Ask for the job in your own words. Your AI opens the skill when it fits.
- It works best when your AI can run code and read your project files.