If you wanna get really good at backend, learn these:
1. Backend Communication Patterns
- REST API
- Request-Response Flow
- Sync vs. Async
- Polling, Server-Sent Events (SSE), Producer-Consumer Pattern
2. Protocols
- TCP/UDP
- WebSockets
- WebRTC
- gRPC
3. Databases & Data Persistence
- SQL Databases: PostgreSQL or MySQL
- Core Concepts: ACID Transactions, Normalization, Joins
- NoSQL Databases
- Key-Value
- ORMs
- Database Scaling: Indexing, Read Replicas, Sharding
4. Architecture & System Design
- Monolith vs. Microservices
- Design Patterns: MVC, Singleton, Factory
- Horizontal vs. Vertical Scaling
- Stateless vs. Stateful Architecture
- Load Balancers, CDNs
- Message Brokers / Queues
5. Application Security
- Authentication
- Session-based (cookies) vs. Token-based (JWTs)
- OAuth 2.0 & OpenID Connect
- Authorization
- OWASP Top 10: Common vulnerabilities (SQL Injection, XSS, Broken Control)
-CORS
Now maybe get familiar with devops tool and all those jargons that makes you feel like you are doing rocket science.