backend-patterns

Backend Patterns - Backend Architecture Design and API Development Best Practices

Skill Overview

Backend Patterns is a comprehensive collection of backend architecture design patterns covering API design, database optimization, caching strategies, authentication and authorization, and other core knowledge for Node.js and Next.js backend development. It helps developers build scalable, high-performance server-side applications.

Applicable Scenarios

1. Node.js/Express backend project development

When you need to build RESTful APIs, implement user authentication, or handle database query optimization, this set of patterns provides a complete architectural reference from Repository to Service Layer, especially suitable for medium-sized Node.js backend projects.

2. Next.js API Routes performance optimization

For full-stack applications built with Next.js, the query optimization, caching strategies, and error-handling patterns in this skill can be applied directly to API Routes to solve common performance bottlenecks and N+1 query issues.

3. Enterprise-level backend architecture design

When a project needs to handle high concurrency, implement complex authentication and authorization logic, or introduce a Redis caching layer, these proven patterns can help you design a stable and reliable backend architecture.

Core Functionality

1. API design and architecture patterns

Provides complete implementation examples of RESTful API structure design, the Repository pattern, Service Layer pattern, and Middleware pattern. These patterns help you separate concerns, improve code testability and maintainability, and are particularly suitable for TypeScript-based Node.js projects.

2. Database optimization and caching strategies

Covers query optimization techniques (such as selecting only required columns), bulk solutions to the N+1 query problem, database transaction patterns, as well as implementations of a Redis caching layer and the Cache-Aside pattern. These techniques can significantly improve application performance and reduce database load.

3. Authentication, authorization, and security protections

Includes JWT token validation, role-based access control (RBAC), rate limiting implementations, and other security patterns. Also provides centralized error handling and an exponential backoff retry mechanism to help build robust backend services.

Frequently Asked Questions

What is the difference between the Repository pattern and the Service Layer?

The Repository pattern is responsible for encapsulating data access logic and providing a unified interface to operate the database; the Service Layer pattern encapsulates business logic and coordinates multiple Repositories to complete complex business operations. Using both together achieves separation of concerns and improves code testability and maintainability.

How to effectively prevent the N+1 query problem?

The key is to fetch data in bulk. Do not query related data one by one inside a loop; instead, first collect all the needed IDs, then use a single bulk query to fetch all related data, and associate them via a Map. This way you can optimize N+1 queries into 2 queries.

How to implement role-based permission control with JWT authentication?

Include the user's role information in the JWT payload. After validating the token, extract the role and check whether the user has permission to perform a certain action using a predefined role-permission mapping. You can implement a requirePermission higher-order function to wrap API handlers that require permission control.