System Design & Common System Design Components

 

1. Understand the Basics of System Design

• Scalability: How to design systems that can scale horizontally (adding more machines) or vertically (adding more power to existing machines).
• Reliability: Ensuring the system is available and fault-tolerant, with redundancy and failover strategies.
• Performance: Designing for low latency, high throughput, and efficient resource usage.
• Consistency vs. Availability: Understanding trade-offs between consistency, availability, and partition tolerance (CAP theorem).
• Security: Implementing authentication, authorization, and encryption.
• Cost: Keeping the design cost-effective, balancing between performance and expense.

2. Familiarize Yourself with Common System Design Components

• Load Balancers: Distribute incoming traffic across multiple servers.
• Caching: Use in-memory storage (e.g., Redis, Memcached) to speed up responses.
• Databases: Understand when to use SQL vs. NoSQL, and concepts like sharding, replication, and indexing.
• Message Queues: Use queues (e.g., Kafka, RabbitMQ) for decoupling services and handling asynchronous tasks.
• Microservices: Design systems using loosely coupled, independently deployable services.
• CDNs: Content Delivery Networks for distributing content closer to users.
• Rate Limiting: Preventing abuse and ensuring fair usage by limiting the number of requests a user can make.

1. Frontend (ReactJS):

"The frontend is built using ReactJS, where users interact with our application. React provides a fast, responsive user experience and communicates with the backend via APIs."

2. Backend (NodeJS):

"The backend is built with NodeJS. It handles API requests from the frontend, processes business logic, and communicates with the database. It also manages background jobs and integrates with external services."

3. Database (MongoDB):

"MongoDB is our main database. We use it to store user data and application data in a flexible, document-based format. It supports high scalability and replication for fault tolerance."

4. Caching (Redis):

"To improve performance, we use Redis for caching frequently accessed data. This reduces the load on the database and speeds up response times."

5. Background Jobs (BullMQ + Redis):

"For handling background tasks like sending emails or processing data, we use BullMQ. It manages job queues, with Redis storing the job data and providing a fast way to queue and process tasks in the background."

6. Infrastructure (AWS):

"The entire system is hosted on AWS. We use various AWS services like EC2 for servers, S3 for file storage, and CloudFront for CDN. AWS also allows us to auto-scale based on traffic to handle peak loads."

7. Monitoring (Kibana):

"For monitoring and logging, we use Kibana. It helps us track system performance, log errors, and troubleshoot issues by visualizing logs and metrics from our services."

---

Architecture Overview:

1. User Interaction: Users interact with the React frontend.
2. API Requests: React sends API requests to the NodeJS backend.
3. Database Access: NodeJS retrieves or writes data to MongoDB.
4. Caching Layer: Frequently accessed data is cached in Redis to improve speed.
5. Background Jobs: BullMQ queues jobs (like data processing or notifications) with Redis managing the job states.
6. AWS Infrastructure: The entire system is deployed on AWS with auto-scaling and load balancing.
7. Monitoring: Kibana tracks logs and performance metrics to ensure the system runs smoothly.

This architecture is scalable, efficient, and well-suited for handling a large number of users and background processes.