In this article, I describe a developer's skill levels using terms like Familiarity, Knowledge, Understanding, Deep Understanding, Ability, Proficiency, and Mastery.

1. Familiarity: You've aware of the concept or tool and have used it in actual projects, but you're not yet comfortable with how everything works.
2. Knowledge: You understand the basic ideas and some more complex parts, but there's still more to learn, especially about the most advanced features.
3. Understanding: You have a solid understanding, including some of the more complex aspects. You're able to solve common issues and can explain how things work to others.
4. Deep Understanding/Ability: You have expert-level knowledge and can identify the pros and cons. You're adept at applying this knowledge to a variety of projects.
5. Proficiency: You have a high level of skill and can use the concept or tool effectively and efficiently.
6. Mastery: You have an outstanding level of expertise, with a deep and comprehensive understanding that enables you to innovate and teach the subject.

Junior Server Side Game Developer Roadmap

1. Server-Side Basics:

1. Ability to implement authentication and authorization mechanisms.
2. Ability in server-side caching techniques.
3. Deep Understanding of database management (SQL and NoSQL).
4. Understanding of server-side architectures (e.g., client-server, peer-to-peer).
5. Understanding of networking principles (TCP/IP, HTTP, WebSockets).
6. Understanding of RESTful APIs and GraphQL.

2. Programming Languages and Frameworks:

1. Proficiency in version control using Git.
2. Ability to use at least one server-side language (e.g., Node.js, Python, Java).
3. Ability to write unit tests and integration tests.
4. Understanding of asynchronous programming and event-driven architecture.
5. Understanding of ORMs and database interaction.
6. Familiarity with real-time communication (WebRTC, socket.io).

3. Scalability and Performance:

1. Proficiency in profiling and benchmarking server-side applications.
2. Ability to optimize database queries for performance.
3. Understanding of session management in a distributed environment.
4. Understanding of microservices architecture.
5. Knowledge of caching strategies and content delivery networks.
6. Familiarity with load balancing and horizontal scaling.

4. Security:

1. Proficiency in security testing and penetration testing.
2. Ability to implement rate limiting and DDoS protection.
3. Deep Understanding of SSL/TLS and secure communication.
4. Understanding of encryption and hashing techniques.
5. Understanding of secure coding practices.

5. DevOps and Deployment:

1. Proficiency in automating deployment.
2. Ability to set up logging and monitoring systems.
3. Understanding of cloud services (AWS, Azure, GCP).
4. Knowledge of infrastructure as code (Terraform, Ansible).
5. Knowledge of continuous integration and continuous deployment (CI/CD).
6. Familiarity with containerization (Docker, Kubernetes).

Please remember that this plan is based on what I know and have seen, and the real steps you take might change depending on your own situation and what the job you want needs. Always learning new things and keeping up with the newest tech is important to do well in this area.