An AWS System Administrator is responsible for managing, configuring, and maintaining cloud-based infrastructure within the Amazon Web Services (AWS) environment. They ensure system reliability, security, and performance by monitoring resources, implementing best practices, and troubleshooting issues. Their duties often include managing EC2 instances, configuring IAM roles, setting up networking components, and optimizing cost efficiency. Additionally, they may automate tasks using scripts and tools like AWS CLI, CloudFormation, or Terraform. This role is critical for ensuring a secure, scalable, and high-performing cloud infrastructure.