System Design


# Hello World!

Welcome to my blog! This is a sample post to demonstrate the new features of the blog system.

## Features

- Markdown support
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```javascript
function hello() {
  console.log('Hello, World!');
}
```

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- Unordered list
- Another item
- And another

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## Horizontal Rule

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That's all for now! Stay tuned for more posts.


Welcome to my blog! This is a sample post to demonstrate the new features.

Hello World


# Understanding JWT Authentication

JSON Web Tokens (JWT) have become the standard for implementing authentication in modern web applications. At Nike, we implemented a robust JWT-based authentication system that could handle millions of users securely.

# Key Components

Our JWT implementation consisted of several key components:

- Token Generation and Validation
- Secure Storage and Transmission
- Refresh Token Mechanism
- Rate Limiting and Security Measures

# Implementation Details

## Token Structure

We structured our JWTs with the following claims:

- `sub`: Subject (user ID)
- `iat`: Issued at time
- `exp`: Expiration time
- `aud`: Audience (application identifier)
- Custom claims for role-based access

## Security Measures

To ensure maximum security, we implemented:

- Short-lived access tokens (15 minutes)
- Secure HTTP-only cookies for refresh tokens
- CSRF protection
- Rate limiting on authentication endpoints
- Token blacklisting for revoked tokens

# Best Practices

Here are some key best practices we followed:

1. Always validate token signatures
2. Use strong encryption algorithms (RS256)
3. Implement proper token revocation
4. Monitor for suspicious activities
5. Regular security audits

# Lessons Learned

The implementation taught us valuable lessons about:

- Importance of proper token management
- Need for comprehensive security measures
- Value of monitoring and logging
- Benefits of standardized authentication 

A deep dive into implementing secure JWT-based authentication for vendor-agnostic systems.

Implementing Secure JWT Authentication


# Microservices at Scale

Implementing microservices architecture at Nike's scale presented unique challenges and opportunities. This post shares our key learnings and best practices.

# Core Principles

Our microservices implementation was guided by these principles:

- Single Responsibility
- Loose Coupling
- High Cohesion
- Independent Deployment
- Fault Isolation

# Architecture Patterns

## Service Communication

We implemented several patterns for service communication:

- Synchronous: REST APIs for direct communication
- Asynchronous: Message queues for event-driven architecture
- API Gateway: For request routing and aggregation
- Service Mesh: For service-to-service communication

## Data Management

Key considerations for data management:

- Database per service
- Event sourcing for data consistency
- CQRS for read/write separation
- Distributed transactions where necessary

# Operational Excellence

## Monitoring and Observability

We implemented comprehensive monitoring:

- Distributed tracing
- Centralized logging
- Metrics collection
- Alert management
- Performance monitoring

## Deployment Strategy

Our deployment approach included:

- Containerization with Docker
- Kubernetes for orchestration
- CI/CD pipelines
- Blue-green deployments
- Canary releases

# Challenges and Solutions

## Common Challenges

1. Service Discovery
2. Configuration Management
3. Distributed Tracing
4. Data Consistency
5. Network Latency

## Our Solutions

- Service mesh for service discovery
- Centralized config management
- Distributed tracing with Jaeger
- Eventual consistency patterns
- Caching strategies

# Best Practices

1. Start with a monolith
2. Break services by business capability
3. Implement proper monitoring
4. Use API versioning
5. Implement circuit breakers
6. Design for failure
7. Maintain documentation 

Key learnings and best practices from implementing microservices at scale.

Blogs : Writing on software.

System Design

Hello World

Implementing Secure JWT Authentication

Microservices Best Practices