Understanding DevOps vs. Site Reliability Engineering (SRE)

By Monika Mueller

DevOps and site reliability engineering (SRE) are becoming more mainstream as the adoption of both practices continues to build. And for good reason. Both disciplines are focused on bridging the gap between development and operations to make delivery faster, more efficient and more reliable. Automation and close collaboration across teams lie at the heart of both disciplines.

However, while DevOps is focused on core development, SRE is concerned with the implementation of this core. Though engineers from both areas collaborate closely, there are distinct differences in the focus and responsibilities of each group. Let’s start by looking at the core focus of each practice.

DevOps: Eliminating Silos to Speed Up Delivery

The core focus of DevOps is delivery of the product. These engineers are focused on automating the development pipeline in order to solve business problems and deploy apps faster. They do this by breaking down silos between development and operations and fostering close communication and collaboration.

At the core of these efforts is a continuous integration / continuous deployment (CI/CD) pipeline. DevOps engineers must have the ability to write clean code in multiple languages that integrate with cross-team development in any environment. They are tasked with developing, designing and deploying core features.

SRE: Ensuring Reliability and Stability

The core focus of SREs is the quality of the product. As the name implies, site reliability engineers are primarily concerned with the reliability of apps that are in production. Once the code has been delivered, it’s the job of SREs to ensure that it’s working as it should. So while DevOps teams are entrenched in the world of development, SREs are immersed in production.

SREs work closely with DevOps engineers to focus on implementation and automation that reduces incidents and improves both reliability and scalability. SREs take a proactive approach to identify issues — and correct them — before they occur, which contributes significantly to both speed and efficiency (a shared focus of DevOps).

What the Collaboration Looks Like in Practice

The development process starts with a software engineer writing code for a new feature. Once the code is written, the DevOps engineer collects it and puts it into a pipeline where the code is tested, packaged and delivered to the end user.

The DevOps engineer owns the process from the moment the code is written until the new feature gets into the hands of the end user. This new code may require new infrastructure, patches or other new resources, all of which is provided by DevOps engineers.

SREs work closely with DevOps engineers to make sure that once the code is delivered, it’s working as expected. And when issues are identified, SREs not only identify the problem, but complete root cause analysis and make sure they don’t happen again. This is achieved through extensive logging, testing, monitoring and predictive analytics.

Consider the analogy of a car being manufactured. Software developers create the engine of the car, put the wheels on it and build the core components. DevOps engineers then make sure that everything is in order for the car to be delivered from the factory to the end user. It’s the job of SREs to make sure that the car performs exactly as it should.

A Shared Goal With Many Benefits

Ultimately, both DevOps and SREs promote speed, efficiency, reliability and scalability. SREs help DevOps continuously deliver results to users by preventing issues and improving reliability. A culture of collaboration is at the core of this shared goal and both DevOps engineers and SREs work closely with the product group.

SREs and DevOps bring different perspectives to a shared goal. With their expertise on the production side of the equation, SREs can provide input and make suggestions for the development team. This constant flow of feedback helps to limit issues with the new functionality. In this way, SRE is an essential component of a DevOps program, and each discipline enhances the other.