Becoming a backend developer in 6 months is an ambitious goal, but with dedication and a structured learning plan, it's definitely achievable. Here's a roadmap to guide you through the essential skills and technologies for a backend developer:

Month 1-2: Fundamentals and Basic Web Development
HTML, CSS, and JavaScript:

Learn the basics of HTML for creating the structure of web pages.
Understand CSS for styling web pages.
Get familiar with JavaScript for client-side interactions.
Version Control (Git):

Learn the basics of version control with Git.
Understand commands like commit, push, pull, merge, and branch.
Basic Command Line Usage:

Get comfortable with the command line interface (CLI).
Learn basic commands for navigation, file manipulation, and system information.
Month 3-4: Server-side Programming and Databases
Programming Language:

Choose a backend programming language such as Python (Django or Flask), JavaScript (Node.js), Ruby (Ruby on Rails), or Java.
Understand the basics of the chosen language.
Server-side Framework:

Learn a backend framework associated with your chosen language (e.g., Django, Express.js, Ruby on Rails, Spring Boot).
Database Fundamentals:

Understand database concepts (relational databases, SQL).
Learn how to perform basic CRUD operations (Create, Read, Update, Delete).
Database Management System (DBMS):

Get hands-on experience with a popular DBMS like MySQL, PostgreSQL, or MongoDB.
Month 5: APIs and Authentication
RESTful APIs:

Understand the principles of RESTful API design.
Learn how to create APIs and handle HTTP methods.
Authentication and Authorization:

Learn about user authentication and authorization mechanisms.
Understand concepts like JWT (JSON Web Tokens) for secure communication.
Month 6: Advanced Topics and Deployment
Middleware and Caching:

Learn about middleware components and their role in backend development.
Understand caching mechanisms to optimize performance.
Testing:

Learn about unit testing and integration testing for backend code.
Understand the importance of testing in maintaining code quality.
Deployment and DevOps:

Learn how to deploy applications to cloud platforms (e.g., AWS, Heroku, or Azure).
Understand basic DevOps principles, including CI/CD (Continuous Integration/Continuous Deployment).
Security Best Practices:

Learn about common security vulnerabilities and best practices to secure your backend code.
Ongoing Learning:
Stay updated with the latest developments in backend technologies.
Contribute to open-source projects or work on personal projects to gain practical experience.
Participate in forums, online communities, and attend meetups to connect with other developers.
Remember, practical experience is crucial in backend development. Try to build projects and solve real-world problems to reinforce your learning. Adjust the timeline based on your progress and focus on continuous improvement. Good luck!