Programming Language (Python/Node/Java)
Data Structures & Algorithms
Version Control with Git
Relational Databases (PostgreSQL/MySQL)
SQL & Database Design
RESTful API Design
Authentication & Authorization (JWT)
NoSQL Databases (MongoDB/Redis)
Web Frameworks (Django/Express/Spring)
Caching Strategies
Message Queues (RabbitMQ/Kafka)
Docker & Containerization
API Security Best Practices
Testing & Unit Tests
Cloud Deployment (AWS/GCP)