System Architecture

Technology-agnostic system design, pick the pattern and the tech BEFORE touching framework mechanics.

Why use it

• Jumping straight to schemas and modules bakes in an architecture nobody chose.
• "Which database / queue / API style?" answered by habit rather than by the actual constraints.
• Migrations and scale limits discovered after the build, not before it.

What it does

• Architecture-pattern selection with trade-offs, monolith → modular monolith → microservices → event-driven → CQRS → event sourcing → hexagonal → clean → API gateway.
• System-design workflows: capacity planning, API design, schema design, scalability assessment, migration planning.
• Technology-decision frameworks: database, cache, message queue, auth, frontend, cloud, API style.
• A lean map over three references, read the map, open the one that matches the question.

Benefits

• Make the expensive call once. Pattern and tech chosen deliberately, and written down.
• No accidental architecture. You stop inheriting a shape nobody picked.
• Scale problems surface on paper, while they still cost nothing to fix.
• Stack-agnostic. Pairs with whatever framework skill you already run.

Install

Download this skill and copy the system-architecture folder to .claude/skills/system-architecture/ in your project, or to ~/.claude/skills/system-architecture/ to use it in every project. Claude Code finds it on its own; you can also call it with /system-architecture.

Part of the Agent Engineering bundle. To get the whole set as a Claude Code plugin: /plugin marketplace add endorphin-ai/hasbrains-agent-kit, then /plugin install agent-engineering@hasbrains-agent-kit.

Source: endorphin-ai/hasbrains-agent-kit. License: MIT.