Systems Engineers require 3 things
1.Foundational understanding of the parts that make up your system.
2.Previous experience leveraging the technologies involved, and there common limitations.
3.How best to manage the overall complexity of the system in the short and long term.
For example if you are trying to build a e-commerce website, as a systems engineer you would need to
- Understand the software required(middle ware app, database, and operating system)
- understand the limitations of each system(sql server may not scale, middle ware may need caching, dns and other setup, operating system security)
- If the companies grows, can we keep this setup simple and scalable.