defense-in-depth

Implement four-layer validation across entry points, business logic, environment guards, and debug instrumentation.

Updated Aug 23, 2026

Search Tags:#quality assurance #security #bug prevention #system design #validation #data integrity #robustness

One-click install

npx skills add https://github.com/vanmarkic/credit-castor --skill defense-in-depth-vanmarkic

Or copy as Structured Prompt for Agent▼

Please help me install this Agent Skill.
Skill: defense-in-depth
Source: https://github.com/vanmarkic/credit-castor/tree/main/.claude/skills/defense-in-depth
Command: npx skills add https://github.com/vanmarkic/credit-castor --skill defense-in-depth-vanmarkic

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill prevents bugs caused by invalid data from ever reaching critical system layers by implementing validation at every possible checkpoint. It transforms single-point fixes into structural impossibility for bugs.

Core Features & Use Cases

Four-Layer Validation: Guides through entry point, business logic, environment guards, and debug instrumentation.
Systemic Bug Prevention: Ensures different code paths or refactorings cannot bypass validation.
Use Case: After fixing a bug where an empty directory caused a critical system failure, use this skill to add validation at the API entry, business logic, and environment levels, making that specific bug impossible to reproduce.

Quick Start

I've fixed a bug caused by invalid user input. Use the defense-in-depth skill to add robust validation at multiple layers.