Amazon Kiro Development Methodology ― Comparative Analysis of Agile and Waterfall Perspectives¶

1. Development Methodology Overview¶

Kiro, announced by Amazon in 2025, adopts a new development methodology that combines characteristics of traditional Waterfall and Agile development. This methodology is called "Spec-Driven Development" and leverages benefits of both development approaches by centering on specifications while incorporating continuous updates and automation.

2. Spec-Driven Development Structure¶

Core Three Specification Files¶

Kiro generates the following three specification files at project initiation:

File Name	Role	Content
`requirements.md`	Requirements Specification	Functional requirements, non-functional requirements, constraints
`design.md`	Design Specification	Architecture, data models, interfaces
`tasks.md`	Task Definition	Implementation tasks, priorities, dependencies

These files are continuously updated by AI agents, maintaining the latest state at all times.

Implementation of Single Source of Truth (SSOT)¶

These three specification files function as the project's "Single Source of Truth," solving the following problems:

Recognition gaps due to information fragmentation
Document obsolescence
Divergence between specifications and implementation

3. Waterfall-oriented Aspects¶

Specification-First Approach¶

graph TD
    A[Requirements Definition] --> B[Design]
    B --> C[Task Decomposition]
    C --> D[Implementation]
    D --> E[Testing]

    style A fill:#e1f5e1
    style B fill:#e1f5e1
    style C fill:#f5f5e1
    style D fill:#e1e1f5
    style E fill:#e1e1f5

Kiro incorporates the "planning-first" philosophy from Waterfall development. By generating three specification files upfront, it provides project overview and enables early detection of potential issues.

Ensuring Traceability¶

Traceability from requirements to design, design to implementation is automatically managed. Kiro's hook system tracks all changes and maintains consistency between specifications and implementation.

Commit → Hook Trigger → Spec-Code Diff Detection → Auto Update
         ↑                                           ↓
         └──────────── Feedback ────────────────────┘

4. Agile-oriented Aspects¶

Continuous Feedback¶

Kiro automatically executes checks at timings such as file saves, commits, and pull requests.

# On file save
def on_save():
    run_tests()
    check_lint()  
    scan_security()
    update_specs()

# Immediate feedback
if issues_found:
    notify_developer()
    suggest_fixes()

This continuous feedback enables early problem detection and minimizes correction costs.

Handling Changes¶

While specification changes carried high costs in traditional Waterfall, Kiro's specifications are designed to be dynamically updated.

Change Management Structure

Specification changes are automatically tracked
Impact scope is automatically analyzed
Related tasks are automatically updated

5. Hybrid Structure Analysis¶

Dual-Track Agile Implementation¶

Kiro implements the concept of "Dual-Track Agile":

Discovery Track: Continuous improvement and updates of specifications
Delivery Track: Automated implementation by AI agents

These two tracks run in parallel, achieving efficient development.

Human-AI Role Division¶

Role	Human	AI
Strategic Planning	◎	△
Specification Approval	◎	×
Implementation	△	◎
Test Execution	△	◎
Quality Check	○	◎

This role division realizes both development speed and quality.

6. Development Methodology Features and Benefits¶

Key Features¶

Amazon Kiro's development methodology has the following characteristics:

Balance of Planning and Flexibility: Specification-first yet enables continuous updates
Automation-driven Efficiency: Automated testing and quality checks through hook systems
Traceability Assurance: Consistent tracking from requirements to implementation possible

Benefits of Adoption¶

Aspect	Traditional Development	Kiro Methodology
Specification Change Costs	High	Low
Document Maintenance	Manual	Automated
Quality Assurance	Post-process	Continuous
Development Speed	Standard	High-speed

Summary

Spec-Driven: Generate requirements.md, design.md, tasks.md upfront as single source of truth
Waterfall-oriented: Emphasizes specification-first, process clarity, traceability
Agile-oriented: Minimizes change costs through immediate testing & iterative updates via Hooks
Conclusion: Kiro is a hybrid development methodology combining "Waterfall ensuring specification coverage" with "Agile emphasizing continuous iteration"
Classification: Closest to Dual-Track Agile / iterative V-Model loops