Implementation Approach

Implementation Strategy Selection Framework (Meta-cognitive Approach)

An implementation strategy selection framework based on meta-cognitive thinking. Derives optimal implementation approaches through a systematic decision process from understanding existing implementations to constraint compatibility.

Meta-cognitive Strategy Selection Process

Step 1: Comprehensive Current State Analysis

Core Question: "What does the existing implementation look like?"

Analysis Framework

Architecture Analysis:
  - Current responsibility separation and improvement potential
  - Data flow identification and evaluation
  - Dependency visualization and impact scope
  - Technical debt quantification

Implementation Quality Assessment:
  - Code quality and maintainability
  - Test coverage and reliability
  - Performance characteristics
  - Security considerations

Historical Context Understanding:
  - Why did it become the current form?
  - Validity check of past decisions
  - Changes in technical constraints
  - Evolution of business requirements

Meta-cognitive Question List

• What is the true responsibility of this implementation?
• Which parts are business essence and which derive from technical constraints?
• What dependencies or implicit preconditions are unclear from the code?
• What benefits and constraints does the current design bring?

Step 2: Strategy Exploration and Creation

Core Question: "When determining before → after, what implementation patterns or strategies should be referenced?"

Strategy Discovery Process

Research and Exploration:
  - Implementation examples and patterns from similar tech stacks (research online)
  - Approach collection from projects handling similar challenges
  - Open source implementation references
  - Technical literature and blog research

Creative Thinking:
  - Sequential/parallel application of multiple strategies
  - Design based on project time/human/technical constraints
  - Phase division and milestone setting
  - Pre-design of necessary extension points

Reference Strategy Patterns (Creative Combinations Encouraged)

Legacy Handling Strategies:

• Strangler Pattern: Gradual migration through phased replacement
• Facade Pattern: Complexity hiding through unified interface
• Adapter Pattern: Bridge with existing systems

New Development Strategies:

• Feature-driven Development: Vertical implementation prioritizing user value
• Foundation-driven Development: Foundation-first construction prioritizing stability
• Risk-driven Development: Prioritize addressing maximum risk elements

Integration/Migration Strategies:

• Proxy Pattern: Transparent feature extension
• Decorator Pattern: Phased enhancement of existing features
• Bridge Pattern: Flexibility through abstraction

Important: The optimal solution is discovered through creative thinking according to each project's context.

Step 3: Risk Assessment and Control

Core Question: "What risks arise when applying this to existing implementation, and what's the best way to control them?"

Risk Analysis Matrix

Technical Risks:
  - Impact on existing systems
  - Data consistency assurance
  - Performance degradation possibility
  - Integration complexity

Operational Risks:
  - Service availability impact
  - Deployment downtime
  - Monitoring/operation process changes
  - Failure rollback procedures

Project Risks:
  - Schedule delay possibility
  - Technology learning costs
  - Quality requirement achievement
  - Cross-team coordination complexity

Risk Control Strategies

Preventive Measures:
  - Phased migration to new system without service disruption
  - Verification through parallel operation of old and new systems
  - Addition of integration and regression tests for new features
  - Pre-implementation setup of performance and error monitoring

Incident Response:
  - Clarify rollback procedures and conditions to old system
  - Prepare log analysis and metrics dashboards
  - Define communication system and role assignments for failures
  - Document partial service continuation procedures

Step 4: Constraint Compatibility Verification

Core Question: "What are this project's constraints?"

Constraint Checklist

Technical Constraints:
  - Compatibility with existing libraries/frameworks
  - Server resource, network, database capacity limits
  - Mandatory requirements like data protection, access control, audit logging
  - Numerical targets like response time  L2 > L3 in order of verifiability importance

## Integration Point Definitions

Define integration points according to selected strategy:
- **Strangler-based**: When switching between old and new systems for each feature
- **Feature-driven**: When users can actually use the feature
- **Foundation-driven**: When all architecture layers are ready and E2E tests pass
- **Hybrid**: When individual goals defined for each phase are achieved

## Anti-patterns

- **Pattern Fixation**: Selecting only from listed strategies without considering unique combinations
- **Insufficient Analysis**: Skipping Step 1 analysis framework before strategy selection
- **Risk Neglect**: Starting implementation without Step 3 risk analysis matrix
- **Constraint Ignorance**: Deciding strategy without checking Step 4 constraint checklist
- **Rationale Omission**: Selecting strategy without using Step 6 documentation template

## Guidelines for Meta-cognitive Execution

1. **Leverage Known Patterns**: Use as starting point, explore creative combinations
2. **Active Web Research**: Research implementation examples from similar tech stacks
3. **Apply 5 Whys**: Pursue root causes to grasp essence
4. **Multi-perspective Evaluation**: Comprehensively evaluate from each Step 1-4 perspective
5. **Creative Thinking**: Consider sequential application of multiple strategies and designs leveraging project-specific constraints
6. **Clarify Decision Rationale**: Make strategy selection rationale explicit in design documents

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [shinpr](https://github.com/shinpr)
- **Source:** [shinpr/agentic-code](https://github.com/shinpr/agentic-code)
- **License:** MIT

Install and usage instructions live in the source repository linked above.