(A) Architecture

The Architecture phase defines the high-level structure of your system. This is where you make fundamental decisions about how components interact, how the system scales, and what patterns you'll use.

Why Architecture Matters

Good architecture:

• Enables scale - Supports growth without major rewrites
• Reduces complexity - Clear boundaries and responsibilities
• Improves maintainability - Easy to understand and modify
• Facilitates collaboration - Multiple teams can work independently

Key Architectural Decisions

1. Microfrontends Architecture

When to use:

• Multiple teams working on the same product
• Need independent deployment
• Different tech stacks per team
• Large codebase that's hard to maintain

Relevant Content:

• Microfrontend Architecture - Complete microfrontends guide
• Routing Orchestration - How to handle routing across MFE
• CSS Isolation - Preventing style conflicts
• Shared State Across MFE - State management in MFE
• Deployment Strategies - Independent deployments
• Error Boundaries Between MFE - Error isolation

Decision Framework:

Use Microfrontends if:
✅ 10+ developers
✅ Multiple teams
✅ Need independent releases
✅ Different tech stacks

Avoid if:
❌ Small team (< 5 developers)
❌ Single product
❌ Tight coupling needed

2. Real-Time Architecture

When to use:

• Live updates needed (chat, notifications, collaboration)
• Real-time data synchronization
• Presence indicators
• Live collaboration features

Relevant Content:

• Real-Time Architecture - Real-time systems overview
• WebSocket Management - WebSocket patterns
• Chat Architecture - Chat system design
• Collaborative Editing - Real-time collaboration
• Presence System - User presence
• Live Notifications - Real-time notifications
• Connection Resilience - Handling disconnections

Decision Framework:

Use WebSockets if:
✅ Bidirectional communication
✅ Low latency required (< 100ms)
✅ High message frequency

Use SSE if:
✅ Server-to-client only
✅ Simpler implementation
✅ HTTP/2 multiplexing

Use Polling if:
✅ Low message frequency
✅ Simple requirements
✅ No real-time constraints

3. State Management Architecture

When to use each pattern:

Flux Architecture (Redux):

• Complex global state
• Time-travel debugging needed
• Predictable state updates
• Large team coordination

Atom-Based State (Recoil, Jotai):

• Fine-grained reactivity
• Component-level state needs
• Performance optimization
• Simpler mental model

Signals (Solid.js pattern):

• Maximum performance
• Fine-grained updates
• Reactive primitives
• Modern reactive patterns

State Machines (XState):

• Complex workflows
• UI state machines
• Predictable transitions
• Visual state modeling

Relevant Content:

• Flux Architecture - Redux patterns
• Atom-Based State - Recoil, Jotai
• Signals - Solid.js signals
• State Machines Advanced - XState patterns
• State and Logic Overview - State management guide

Decision Framework:

Use Redux if:
✅ Complex global state
✅ Need time-travel debugging
✅ Large team

Use Recoil/Jotai if:
✅ Fine-grained reactivity
✅ Component-level state
✅ Simpler mental model

Use Signals if:
✅ Maximum performance
✅ Fine-grained updates
✅ Modern reactive patterns

Use XState if:
✅ Complex workflows
✅ UI state machines
✅ Visual modeling needed

4. Architecture Patterns

Component Architecture Patterns:

Compound Components:

• Related components that work together
• Flexible composition
• Shared implicit state

Higher-Order Components (HOC):

• Cross-cutting concerns
• Reusable logic
• Legacy React patterns

Render Props:

• Flexible component composition
• Share logic between components
• Alternative to HOC

Dependency Injection:

• Loose coupling
• Testability
• Flexibility

Plugin Architecture:

• Extensible systems
• Third-party integrations
• Modular design

Event-Driven Architecture:

• Decoupled components
• Pub/sub patterns
• Reactive systems

Relevant Content:

• Compound Components - Component composition
• Higher-Order Components - HOC patterns
• Render Props vs Hooks - Composition patterns
• Dependency Injection - DI patterns
• Plugin Architecture - Extensible systems
• Event-Driven Architecture - Pub/sub patterns
• Inversion of Control - IoC patterns
• Module Pattern - Module organization

Decision Framework:

Use Compound Components if:
✅ Related components
✅ Flexible composition
✅ Shared implicit state

Use HOC if:
✅ Cross-cutting concerns
✅ Legacy codebase
✅ Reusable logic

Use Dependency Injection if:
✅ Loose coupling needed
✅ High testability
✅ Flexibility required

Use Plugin Architecture if:
✅ Extensible system
✅ Third-party integrations
✅ Modular design

5. Rendering Architecture

Rendering Strategies:

Static Site Generation (SSG):

• Static content
• SEO critical
• Fast initial load
• Build-time generation

Server-Side Rendering (SSR):

• Dynamic content
• Personalization needed
• SEO important
• Fresh data required

Incremental Static Regeneration (ISR):

• Mix of static and dynamic
• Balance between speed and freshness
• Large content sites
• Periodic updates

Client-Side Rendering (CSR):

• Highly interactive
• SPA requirements
• No SEO needed
• Rich user interactions

Relevant Content:

• Pre-rendering - SSG/SSR/ISR strategies
• Code Splitting SSR - SSR code splitting

Decision Framework:

Use SSG if:
✅ Static content
✅ SEO critical
✅ Fast load needed

Use SSR if:
✅ Dynamic content
✅ Personalization
✅ SEO important

Use ISR if:
✅ Mix of static/dynamic
✅ Large content sites
✅ Periodic updates

Use CSR if:
✅ Highly interactive
✅ No SEO needed
✅ SPA requirements

6. File Upload Architecture

When to use:

• User-generated content
• Media uploads
• Large file handling
• Progress tracking

Relevant Content:

• File Upload Architecture - High-level file upload design

Architecture Decision Checklist

Use this checklist when designing architecture:

Scale & Team

• Team size considered
• Microfrontends needed?
• Independent deployments required?
• Multiple tech stacks?

Real-Time

• Real-time updates needed?
• WebSocket vs SSE vs Polling?
• Connection resilience?
• Presence indicators?

State Management

• Global state needed?
• State management pattern chosen
• State persistence required?
• State synchronization across tabs?

Component Architecture

• Component patterns chosen
• Composition strategy
• Reusability strategy
• Testing strategy

Rendering

• Rendering strategy chosen
• SEO requirements
• Performance targets
• Update frequency

Data Flow

• Data fetching strategy
• Caching strategy
• State synchronization
• Error handling

Common Architectural Patterns

Monolithic Frontend

Single codebase
Single deployment
Shared state
Simple for small teams

Microfrontends

Multiple codebases
Independent deployments
Shared state via events
Complex but scalable

Modular Monolith

Single codebase
Modular structure
Clear boundaries
Balance of simplicity and scale

Trade-offs

Microfrontends

Pros:

• Independent deployments
• Team autonomy
• Technology diversity
• Scalability

Cons:

• Increased complexity
• Bundle size overhead
• Integration challenges
• Shared state complexity

Real-Time (WebSockets)

Pros:

• Low latency
• Bidirectional
• Efficient

Cons:

• Connection management
• Scaling challenges
• Complexity

State Management (Redux)

Pros:

• Predictable
• Time-travel debugging
• Large ecosystem

Cons:

• Boilerplate
• Learning curve
• Overkill for simple apps

Next Steps

After defining architecture, move to:

• Data Model (D) - Define data flow and state
• Interface (I) - Design UI/UX
• Optimizations (O) - Improve performance

Remember: Architecture is about trade-offs. Choose patterns that fit your team size, scale, and requirements.