As a former DevOps engineer, allow me to clarify exactly what we do. Prior to the introduction of the phrase DevOps, there were network engineers, security engineers, system administrators (Unix and Linux admins), and automation engineers. These roles that combine Cloud and DevOps principles have merged into a single position: DevOps engineer.

1) Automates infrastructure activities using IaC or bash/python scripting.
2) Managing and configuring a cluster of servers
3) Creates and sustains CI-CD pipelines.
4) Secure your servers and cloud services.
Furthermore, DevOps are Linux experts who understand how to build highly distributed systems on the AWS cloud (or any cloud) using microservices, Kubernetes, Amazon ECS/Fargate, or just virtual on-premise servers.

Most importantly, they are the experts in cloud services. They understand how to connect any AWS managed service, including Amazon RDS, Aurora, Amazon S3, and even cloud networking issues (VPC Networking). Furthermore, if you have an intruder in your systems, a server hack, or a traditional Jenkins/WordPress hack, they are usually the ones to research and inspect the root cause, identify the vulnerability, and provide the analysis and solution. Hire a DevOps engineer to ensure that your infrastructure is automated, secure, and extremely efficient.