Architecture Design

Overview

This skill enables you to design comprehensive software solution architectures including system components, technology stacks, integration patterns, scalability strategies, and deployment models.

Core Capabilities

When activated, this skill provides:

1. Requirements Analysis & Architecture Planning

- Analyze functional and non-functional requirements - Identify architectural drivers (scalability, security, performance) - Define system boundaries and constraints - Establish architecture goals and success criteria

1. System Architecture Design

- Design layered/tiered architectures - Create microservices and domain-driven designs - Design event-driven and message-based systems - Plan serverless and cloud-native architectures - Design monolithic, modular monolithic, or distributed systems

1. Technology Stack Selection

- Evaluate and justify programming languages and frameworks - Select databases with rationale (SQL, NoSQL, time-series, graph) - Choose middleware and integration platforms (message queues, API gateways) - Select infrastructure and cloud platforms (assess vendor lock-in) - Recommend CI/CD and DevOps tools - Document technology decisions in ADRs with alternatives considered - Assess team skills and training needs for new technologies

1. Architecture Patterns & Best Practices

- Apply design patterns (MVC, MVVM, Clean Architecture, Hexagonal) - Implement integration patterns (REST, GraphQL, gRPC, message queues) - Design for scalability (horizontal/vertical, caching, CDN) - Implement security patterns (OAuth, JWT, zero-trust) - Apply resilience patterns (circuit breakers, retries, bulkheads)

1. Documentation & Deliverables

- Create C4 model diagrams in Mermaid format (Context, Container, Component, Code) - Generate Mermaid diagrams (class, sequence, deployment) - Produce architecture decision records (ADRs) - Write technical specifications and API contracts - Create implementation roadmaps and migration plans

Architecture Design Workflow

Follow this systematic process:

Step 1: Discovery & Requirements

1. Gather Requirements

- Functional requirements (features, use cases) - Non-functional requirements (performance, scalability, security) - Business constraints (budget, timeline, compliance) - Technical constraints (existing systems, team skills)

1. Analyze Architecture Drivers

- Performance: latency, throughput targets - Scalability: user growth, data volume projections - Availability: uptime SLA, disaster recovery needs - Security: authentication, authorization, compliance requirements - Maintainability: testability, modularity goals

1. Define System Context

- Identify stakeholders and their needs - Map external systems and dependencies - Define system boundaries - Identify integration points

Step 2: Architecture Design

1. Choose Architecture Style

Select based on requirements and constraints:

Monolithic

• Use for: Simple applications, MVPs, small teams, tight deadlines
• Benefits: Simple deployment, strong consistency, no network overhead
• Trade-offs: Scaling limitations, technology lock-in

Modular Monolithic

• Use for: Medium complexity, clear domain boundaries
• Benefits: Better organization, some isolation, shared infrastructure
• Trade-offs: Still single deployment, limited independent scaling

Microservices

• Use for: Large scale, multiple teams, different tech stacks
• Benefits: Independent scaling/deployment, technology flexibility
• Trade-offs: Distributed complexity, network overhead, eventual consistency

Serverless

• Use for: Event-driven, variable load, rapid development
• Benefits: Auto-scaling, pay-per-use, no infrastructure management
• Trade-offs: Cold starts, vendor lock-in, debugging complexity

Event-Driven

• Use for: Real-time processing, loose coupling, high throughput
• Benefits: Scalability, flexibility, asynchronous processing
• Trade-offs: Complexity, eventual consistency, debugging challenges

1. Design System Components

Define key layers and components:

┌─────────────────────────────────┐
│   Presentation Layer            │  UI, Controllers, APIs
├─────────────────────────────────┤
│   Application Layer             │  Use Cases, Orchestration
├─────────────────────────────────┤
│   Domain Layer                  │  Business Logic, Entities
├─────────────────────────────────┤
│   Data Layer                    │  Databases, Caches
├─────────────────────────────────┤
│   Infrastructure Layer          │  External APIs, Services
└─────────────────────────────────┘

1. Define Data Architecture

- Design data models and schemas - Choose database types (relational, document, graph, time-series) - Plan data partitioning and sharding strategies - Design caching layers (Redis, Memcached) - Define data flows and ETL processes

1. Design Integration Points

- API design (REST, GraphQL, gRPC) - Message queues (Kafka, RabbitMQ, SQS) - Event streaming architectures - Authentication and authorization flows - Rate limiting and throttling strategies

Step 3: Document Architecture

1. Create Architecture Diagrams

Use C4 model in Mermaid format for comprehensive documentation:

• Context: System in environment with users and external systems (use Mermaid C4Context)
• Container: High-level technology choices and communication (use Mermaid C4Container)
• Component: Internal structure of containers (use Mermaid C4Component)
• Code: Class diagrams for complex components (use Mermaid classDiagram)

All diagrams should use Mermaid syntax for easy versioning and rendering in markdown.

1. Write Architecture Decision Records (ADRs)

Document all significant decisions using structured ADRs:

# ADR-001: [Decision Title]

## Status
Proposed | Accepted | Deprecated | Superseded

## Context
[Problem and constraints requiring decision]

## Decision
[Chosen solution and approach]

## Consequences
[Benefits and trade-offs]

Full ADR Template: See [adr-template.md](references/adr-template.md) for complete structure with examples

1. Produce Technical Specifications

- System overview and objectives - Component descriptions and responsibilities - API contracts and interfaces - Data models and schemas - Security and compliance measures - Deployment and operations guidelines

Step 4: Validate & Review

1. Quality Attributes Assessment

- Performance: Response time, throughput - Scalability: Horizontal/vertical scaling capabilities - Availability: Fault tolerance, disaster recovery - Security: Authentication, authorization, encryption - Maintainability: Code organization, testability - Cost: Infrastructure and operational expenses

1. Design Validation Checklist

Ensure architecture is review-ready:

• All functional and non-functional requirements addressed
• Architecture style justified with trade-offs documented
• Scalability strategy defined (horizontal/vertical, capacity planning)
• Security measures implemented (authentication, authorization, encryption)
• Data architecture validated (storage, consistency, replication)
• Integration patterns specified (sync/async, APIs, events)
• Monitoring and observability planned (metrics, logs, traces, alerts)
• Disaster recovery and backup strategy documented (RPO/RTO)
• Cost estimates provided (infrastructure, operations, scaling)
• Architecture Decision Records (ADRs) created for major decisions

Reference Files

Load reference files based on specific needs:

• Architecture Design Process: See [architecture-design-process.md](references/architecture-design-process.md) when:

- Need detailed step-by-step guidance for complex architectures - Working through each phase systematically - Require comprehensive checklists and considerations

• Architecture Patterns: See [architecture-patterns.md](references/architecture-patterns.md) when:

- Need detailed pattern descriptions with benefits and trade-offs - Comparing multiple architecture styles - Looking for specific pattern implementations and examples

• Technology Stack Guide: See [technology-stack-guide.md](references/technology-stack-guide.md) when:

- Evaluating specific technologies or frameworks - Need recommendations for databases, languages, or cloud platforms - Comparing technology options for specific requirements

• Best Practices: See [best-practices.md](references/best-practices.md) when:

- Need design principles and guidelines - Looking for API design standards - Require security or operational best practices

• Design Considerations: See [design-considerations.md](references/design-considerations.md) when:

- Evaluating quality attributes (performance, scalability, security) - Need guidance on specific architectural concerns - Planning for observability, resilience, or cost optimization

• Common Anti-Patterns: See [common-anti-patterns-to-avoid.md](references/common-anti-patterns-to-avoid.md) when:

- Reviewing existing architectures for issues - Validating design decisions - Need examples of what NOT to do

• Migration Patterns: See [migration-patterns.md](references/migration-patterns.md) when:

- Modernizing legacy applications - Planning migration strategies - Need patterns for phased migrations or strangler fig approaches

• Examples: See [examples.md](references/examples.md) when:

- Need complete architecture examples for common scenarios - Looking for real-world reference implementations - Want to see how patterns are applied in practice

• Resources and References: See [resources-and-references.md](references/resources-and-references.md) when:

- Need external documentation links - Looking for additional learning resources - Require specifications or standards references

Output Format

Produce clear, comprehensive architecture documentation:

1. Architecture Overview

- System purpose and scope - Key architecture decisions and rationale - High-level component diagram

1. Detailed Design

- Component descriptions and responsibilities - Data models and schemas - API specifications - Integration patterns

1. Diagrams (All in Mermaid format)

- C4 Context diagram (Mermaid C4Context) - C4 Container diagram (Mermaid C4Container) - Sequence diagrams for key flows (Mermaid sequenceDiagram) - Deployment diagram (Mermaid flowchart or C4Deployment)

1. Implementation Roadmap

- Phase breakdown with milestones - Dependencies and sequencing - Resource requirements - Risk mitigation strategies

1. Architecture Decision Records

- Document all significant decisions - Include context, alternatives, and trade-offs