Skip to content

Design Template

Quick Navigation

Use this template to create comprehensive design documents that translate requirements into technical specifications.

Document Information

  • Feature Name: [Your Feature Name]
  • Version: 1.0
  • Date: [Current Date]
  • Author: [Your Name]
  • Reviewers: [List technical reviewers]
  • Related Documents: [Link to requirements document]

Overview

[Provide a high-level summary of the design approach. Explain how this design addresses the requirements and fits into the overall system architecture. Keep this section concise but comprehensive.]

Design Goals

  • [Primary goal 1]
  • [Primary goal 2]
  • [Primary goal 3]

Key Design Decisions

  • [Decision 1 and rationale]
  • [Decision 2 and rationale]
  • [Decision 3 and rationale]

Architecture

System Context

[Describe how this feature fits into the broader system. Include external dependencies and integration points.]

graph TB
    A[External System 1] --> B[Your Feature]
    B --> C[Internal System 1]
    B --> D[Internal System 2]
    E[External System 2] --> B

High-Level Architecture

[Describe the overall architectural approach and major components.]

graph LR
    A[Component 1] --> B[Component 2]
    B --> C[Component 3]
    C --> D[Component 4]

Technology Stack

Layer Technology Rationale
Frontend [Technology] [Why chosen]
Backend [Technology] [Why chosen]
Database [Technology] [Why chosen]
Infrastructure [Technology] [Why chosen]

Components and Interfaces

Component 1: [Component Name]

Purpose: [What this component does]

Responsibilities: - [Responsibility 1] - [Responsibility 2] - [Responsibility 3]

Interfaces: - Input: [What it receives] - Output: [What it produces] - Dependencies: [What it depends on]

Implementation Notes: - [Key implementation detail 1] - [Key implementation detail 2]

Component 2: [Component Name]

Purpose: [What this component does]

Responsibilities: - [Responsibility 1] - [Responsibility 2]

Interfaces: - Input: [What it receives] - Output: [What it produces] - Dependencies: [What it depends on]

Implementation Notes: - [Key implementation detail 1] - [Key implementation detail 2]

Component 3: [Component Name]

Purpose: [What this component does]

Responsibilities: - [Responsibility 1] - [Responsibility 2]

Interfaces: - Input: [What it receives] - Output: [What it produces] - Dependencies: [What it depends on]

Implementation Notes: - [Key implementation detail 1] - [Key implementation detail 2]

Data Models

Entity 1: [Entity Name]

interface EntityName {
  id: string;
  property1: string;
  property2: number;
  property3: boolean;
  createdAt: Date;
  updatedAt: Date;
}

Validation Rules: - [Validation rule 1] - [Validation rule 2]

Relationships: - [Relationship to other entities]

Entity 2: [Entity Name]

interface EntityName {
  id: string;
  property1: string;
  property2: EntityName[];
  status: 'active' | 'inactive' | 'pending';
}

Validation Rules: - [Validation rule 1] - [Validation rule 2]

Relationships: - [Relationship to other entities]

Data Flow

sequenceDiagram
    participant User
    participant Frontend
    participant API
    participant Database

    User->>Frontend: Action
    Frontend->>API: Request
    API->>Database: Query
    Database-->>API: Result
    API-->>Frontend: Response
    Frontend-->>User: Update

API Design

Endpoint 1: [Endpoint Name]

Method: POST
Path: /api/v1/[resource]

Request: 

{
  "property1": "string",
  "property2": "number",
  "property3": "boolean"
}

Response: 

{
  "id": "string",
  "property1": "string",
  "property2": "number",
  "createdAt": "ISO date string"
}

Error Responses: - 400 Bad Request: [When this occurs] - 401 Unauthorized: [When this occurs] - 404 Not Found: [When this occurs]

Endpoint 2: [Endpoint Name]

Method: GET
Path: /api/v1/[resource]/{id}

Parameters: - id (path): [Description] - include (query, optional): [Description]

Response: 

{
  "id": "string",
  "property1": "string",
  "property2": "number"
}

Security Considerations

Authentication

  • [Authentication method and implementation]
  • [Token management approach]

Authorization

  • [Authorization model and rules]
  • [Permission checking strategy]

Data Protection

  • [Data encryption approach]
  • [PII handling procedures]
  • [Data retention policies]

Input Validation

  • [Validation strategies]
  • [Sanitization procedures]
  • [Rate limiting approach]

Error Handling

Error Categories

Category HTTP Status Description User Action
Validation 400 Invalid input data Fix input and retry
Authentication 401 Invalid credentials Re-authenticate
Authorization 403 Insufficient permissions Contact administrator
Not Found 404 Resource doesn't exist Check resource identifier
Server Error 500 Internal system error Retry later or contact support

Error Response Format

{
  "error": {
    "code": "ERROR_CODE",
    "message": "Human-readable error message",
    "details": {
      "field": "Specific field error"
    },
    "timestamp": "ISO date string",
    "requestId": "unique-request-id"
  }
}

Logging Strategy

  • Error Logs: [What gets logged for errors]
  • Audit Logs: [What gets logged for auditing]
  • Performance Logs: [What gets logged for monitoring]

Performance Considerations

Expected Load

  • Concurrent Users: [Number]
  • Requests per Second: [Number]
  • Data Volume: [Size/Growth rate]

Performance Requirements

  • Response Time: [Target response times]
  • Throughput: [Target throughput]
  • Availability: [Uptime requirements]

Optimization Strategies

  • [Caching strategy]
  • [Database optimization approach]
  • [CDN usage]
  • [Load balancing approach]

Monitoring and Metrics

  • [Key performance indicators]
  • [Monitoring tools and dashboards]
  • [Alert thresholds]

Testing Strategy

Unit Testing

  • Coverage Target: [Percentage]
  • Testing Framework: [Framework name]
  • Key Test Areas: [Critical functionality to test]

Integration Testing

  • API Testing: [Approach and tools]
  • Database Testing: [Approach and tools]
  • External Service Testing: [Mocking strategy]

End-to-End Testing

  • User Scenarios: [Key user journeys to test]
  • Testing Tools: [E2E testing framework]
  • Test Environment: [Environment setup]

Performance Testing

  • Load Testing: [Approach and tools]
  • Stress Testing: [Limits to test]
  • Monitoring: [Performance metrics to track]

Deployment and Operations

Deployment Strategy

  • [Deployment approach (blue-green, rolling, etc.)]
  • [Environment progression]
  • [Rollback procedures]

Configuration Management

  • [Configuration approach]
  • [Environment-specific settings]
  • [Secret management]

Monitoring and Alerting

  • [Health checks]
  • [Key metrics to monitor]
  • [Alert conditions and escalation]

Maintenance Procedures

  • [Regular maintenance tasks]
  • [Backup and recovery procedures]
  • [Update and patching strategy]

Migration and Compatibility

Data Migration

  • [Migration strategy if applicable]
  • [Data transformation requirements]
  • [Rollback procedures]

Backward Compatibility

  • [API versioning strategy]
  • [Breaking change procedures]
  • [Deprecation timeline]

Integration Impact

  • [Impact on existing systems]
  • [Required changes to dependent systems]
  • [Communication plan for changes]

Design Review Checklist

Use this checklist to validate your design document:

Architecture

  • [ ] High-level architecture is clearly described
  • [ ] Component responsibilities are well-defined
  • [ ] Interfaces between components are specified
  • [ ] Technology choices are justified

Requirements Alignment

  • [ ] Design addresses all functional requirements
  • [ ] Non-functional requirements are considered
  • [ ] Success criteria can be met with this design
  • [ ] Constraints and assumptions are addressed

Technical Quality

  • [ ] Design follows established patterns and principles
  • [ ] Security considerations are addressed
  • [ ] Performance requirements are considered
  • [ ] Error handling is comprehensive

Implementation Readiness

  • [ ] Design provides sufficient detail for implementation
  • [ ] Data models are complete and validated
  • [ ] API specifications are detailed
  • [ ] Testing strategy is comprehensive

Maintainability

  • [ ] Design supports future extensibility
  • [ ] Components are loosely coupled
  • [ ] Configuration is externalized
  • [ ] Monitoring and observability are included

Design Patterns Reference

Common Patterns to Consider

Creational Patterns: - Factory: When you need to create objects without specifying exact classes - Builder: When constructing complex objects step by step - Singleton: When you need exactly one instance of a class

Structural Patterns: - Adapter: When integrating incompatible interfaces - Decorator: When adding behavior without altering structure - Facade: When simplifying complex subsystem interfaces

Behavioral Patterns: - Observer: When objects need to be notified of state changes - Strategy: When you need to switch between algorithms - Command: When you need to parameterize objects with operations

Architectural Patterns: - MVC/MVP/MVVM: For separating presentation from business logic - Repository: For abstracting data access logic - Unit of Work: For maintaining consistency across multiple operations

← Requirements Template | Tasks Template →