codebase-design

Guide developers in designing deep, testable code modules with clean interfaces and seams.

6|Updated Nov 30, 2025

Search Tags:#deep modules #code design #code testing #dependency assessment #seam discipline

Ready to run

npx skills add https://github.com/christopher-buss/bedrock --skill codebase-design-christopher-buss

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: codebase-design
Source: https://github.com/christopher-buss/bedrock/tree/main/.agents/skills/codebase-design
Command: npx skills add https://github.com/christopher-buss/bedrock --skill codebase-design-christopher-buss

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill helps you design deeper modules in your codebase with clean interfaces and clear seams, enhancing maintainability and testability.

Core Features & Use Cases

Designing Deep Modules: Understand and implement the concept of depth, interfaces, seams, and adaptors to design better code modules.
Dependency Assessment: Assess module dependencies for in-process, local-substitutable, Ports & Adapters, and external (Mock) categories to decide the deepening approach.
Seam Discipline: Follow guidelines on how to effectively place and utilize seams to enhance testing and flexibility.
Testing Strategies: Use the "replace, don't layer" approach for testing to ensure interface-driven testing for robust and maintainable tests.

Quick Start

Utilize the codebase-design skill to guide your team in rethinking the design of a critical module within your application by first analyzing its dependencies and then exploring possible design improvements using the 'Design It Twice' technique.

Frequently Asked Questions about codebase-design

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

What is a deep module in code design and how does it improve maintainability?▼

A deep module in code design features a clean, minimal interface that conceals substantial implementation complexity. This structure enhances maintainability by reducing the surface area exposed to dependencies, making the codebase easier to test and modify without breaking calling components.

How do I assess module dependencies to decide on a deepening approach?▼

Assess module dependencies by categorizing them into in-process, local-substitutable, Ports & Adapters, and external categories. This dependency assessment clarifies how external interactions impact your code structure, guiding the specific deepening strategy needed for each module.

How do I place seams effectively in a codebase to enhance testability?▼

Place seams effectively at boundaries where dependencies require substitution for testing. Proper seam discipline separates interface from implementation, allowing you to replace rather than layer testing components, which ensures interface-driven tests remain robust.

What is the best way to test deep modules without excessive layering?▼

The best way to test deep modules is using the 'replace, don't layer' approach. This strategy focuses on interface-driven testing, substituting dependencies directly through seams rather than adding complex test layers, ensuring tests remain maintainable.

Can I use the Design It Twice technique to improve an existing critical module?▼

Yes, you can use the Design It Twice technique to rethink a critical module's design. Analyze its current dependencies and seams, then explore alternative design improvements to achieve deeper, more testable code structures.

When should I not use deep module design for my application structure?▼

Deep module design may be unsuitable when an application demands extremely shallow, transparent pass-through logic where hiding implementation complexity behind a minimal interface would obscure critical data flow or introduce unnecessary abstraction layers.