Before we begin

• Writing code itself is now fast and relatively easy.
• However, maintaining and operating code is still not easy.
• For PoCs or testing purposes, quickly building and using something can be perfectly reasonable.
• But code that must be run as a service should not be built merely to the point where it “works.”
• From the beginning, it should be designed and implemented with long-term maintenance and operation in mind.

Architecture

Architecture

System Prompt

Skills vs MCP vs SubAgent

MCP (tools)

A “standardized tool-calling interface” that allows LLMs to interact with the external world.

• An abstraction layer for accessing external APIs, databases, file systems, and internal services.
• The LLM only expresses what it wants to do, while the orchestration layer is responsible for actual execution.