SRE vs DevOps: What’s the Difference?

IT SRE vs DevOps

Apps are constantly becoming more complex. That’s why developers are looking for approaches that speed up software creation, release, and deployment. Over the past 10 years, IT teams across the globe have been using DevOps and SRE. When asking SRE vs DevOps, how do these methodologies differ? Which of them is better and more efficient, hence SRE vs DevOps.

Comparison of SRE vs DevOps

DevOps: improved team communication and delivery automation

DevOps is a set of principles and an SDLC philosophy. Developers, testers, and system administrators work closely together. Team members strive to achieve a common goal – to quickly release stable and secure software.

The essence of DevOps

Previously, development teams and IT operations teams worked separately. Developers wrote code and were only responsible for its quality. Operation teams took care of deploying updates in production. When errors occurred in a system during delivery, specialists spend hours and days searching for its source. Developers blamed operations specialists for the unstable deployment environment, and system administrators blamed bugs in the code. Such situations seriously delayed the development process.

The philosophy of DevOps arose as a response to the problems of agility and fragmentation. It brought together all the development participants in a common workflow. There, instability issues resolve long before a release, and most of the operations automated.

How DevOps works

The DevOps process is built on three practices. These are CI/CD, automated testing, and infrastructure as code (IaC). 


DevOps experts automate code deployment and delivery using a CI/CD pipeline. If an individual developer changes pieces of code, these changes are automatically merged into the master branch, automatically tested, built, and delivered. The platform notifies developers, testers, and project managers about all processes through a bug-tracking system.

If such a pipeline is missing, a developer manually tests the code. Then quality assurance specialists check the build and report errors to programmers. And the circle continues. This format of work provokes a mess-up and delays the release of a product.

CI/CD allows you to run developer-written unit tests for new code. An automated system takes code and runs tests. If these tests are successfully completed, the process of “building an app” begins. When the procedure is successful, integration testing starts. Then the build is uploaded to cloud storage or a local server. A link to the build is placed in the version control system, and testers can now manually check the new product version. A DevOps specialist sets up and maintains the pipeline.

The CI/CD process includes not only the delivery of a product but also the control over the app operation in production. It is not enough to deploy software on a server. DevOps experts make sure that the product is reliable and error-free. If a failure occurs, they quickly respond to errors and correct them.

Automated testing

Testing automation is an important part of the DevOps process as it speeds up product quality checks and ensures fast delivery. Autotests also can be used to achieve continuous testing, which is a great addition to CI/CD.

DevOps’ best practice is to run automated tests in a CI/CD pipeline as early and as often as possible. There are dozens of updates every day. Therefore, testing a build should take minutes, not days.

Automated testing supports the main goals of DevOps:

  • It accelerates the release of a high-quality product. Testing takes less time and guarantees almost 100% code testing.
  • Automated testing improves communication within a team. Project participants are responsible for the quality of a product and cooperate with each other.
  • It ensures the reliability of releases. Software problems resolve before a solution goes into production. If errors do occur, the development team quickly fixes them.
  • It provides security. Automated tests run frequently if set up so, so specialists check a product for reliability and compliance with the law.
  • It increases customer loyalty. Automated testing helps to quickly respond to user requests. New functions quickly add to the system and tested. Clients are happy when their opinion is taken into account. They continue to use the app and recommend it to their friends and acquaintances.

Infrastructure as code

In DevOps outsourcing, there is a concept of IaC (infrastructure as code). IaC is the automated management of networks, virtual machines, and operating environments. The infrastructure is treated just like any code. 

Programmers use IaC to develop and run sandbox apps. Testers run tests with copies of product environments to look for bugs. When everything is ready and a software product needs to be deployed, DevOps puts the infrastructure into production.

Specialists do not need to enter the machine and manually configure it. Instead, they write code that describes the desired state of a new machine. The code runs and automatically configures it without human intervention. One operator can set up hundreds of machines at the same time at the push of a button.

Infrastructure, like code, is monitored with the help of a version control system. It is tested and meets the necessary requirements. IaC complements continuous integration, delivery, and testing:

  • It speeds up product releases because administrators don’t have to manually set up the infrastructure.
  • It provides reliability. The infrastructure configures automatically, the configuration stores in separate files. Consequently, a specialist is less likely to make a mistake.

DevOps supports Agile projects (Agile, Scrum, Kanban). According to various studies, it provides projects with the best performance. Likewise, puppet has established that DevOps teams:

  • deploy products 30 times more often;
  • are 60 times less likely to encounter failures;
  • deliver software solutions to production 440 times faster.

SRE: a unique software lifecycle approach

The creator of SRE Google regards site reliability engineering as one of the ways of DevOps implementation. DevOps brings developers, system administrators, and testers into a team and describes what needs completed. So, in this process, SRE is responsible for how to implement the work in a particular case. So, it helps to detect what methods, tools and metrics need to be used so that a software product meets the level of reliability established in an SLA.

The essence of SRE

When production incidents occur, a program crashes. Administrators solve this problem in their own way: they examine log files and restart the service. Developers also examine logs and review code. At the same time, no one can assess the situation comprehensively. In such a case, a service can remain inactive for hours, and a business loses tens of thousands of dollars per hour.

Without system administrators, developers will be able to deploy and maintain services. But the infrastructure may become chaotic. Programmers will not develop the infrastructure because they have numerous product development tasks.

Therefore, companies began to assign a developer fully involved in system support. Such a specialist creates logs, sets up monitoring, cleans modules, refactors code, and so on. An SRE solves infrastructure problems and conducts a review of the code written by developers to assess how it will affect the reliability of a system. The SRE specialist blocks a commit, deployment, or pull request that unnecessarily complicates the app. This IT professional also participates in the choice of architectural solutions.

It is an SRE specialist who looks at the system as a whole, without separating code, infrastructure, deployment methods, OS, etc. They do not turn to administrators when an OS or a network needs to be set up. They don’t contact developers when it is necessary to correct the code and figure out what is written there. Such an expert solves problems on their own and ensures the reliability of an app.

How SRE works

Developers and administrators have different ideas about system reliability. So, an SRE specialist offers specific targets that the team focuses on. Moreover, these are an SLA, an SLO, and an SLI.

An SLO collects availability metrics that an SRE engineer sets up with the product owner. For example, such a metric might be: “The service should function 99.99% of the time.” An SLI contains specific numerical parameters (site response time, percentage of bugs). The SLO and the SLI mean internal documents used by developers. In an SLA, it records a company’s obligations to customers and fines for its violation.

An SRE specialist and a team operate within an Error budget (the maximum amount a business can afford to lose due to system failures). For example, the upper limit is 30 downtimes per month. This means that the team must arrange work activities so as not to go beyond these limits. If developers spend 25 downtimes in two weeks, they will have to suspend the release of new features and fix bugs. When your reserve is large, you can experiment, update, and test the software.

SRE vs DevOps comparison

Site reliability engineering can become part of the DevOps process. Both practices make teams united and focused on the same result – stable releases of high-quality software. But they also have differences:

  • SRE has a narrow focus. It must reduce the frequency, duration, and consequences of system failures. DevOps is a broad concept including CI/CD practices, automated testing, IaC, and SRE.
  • DevOps gives an example of how to build communication within a team. SRE prescribes specific steps for how the development and operations teams should interact to build an efficient high-quality product.
  • DevOps performance metric is the speed of creating and delivering software. SRE’s main goal is to make a site reliable and accessible.
  • An SRE team consists of one or a few Site Reliability Engineers. A DevOps team includes everyone involved in the software development process.
  • DevOps needs CI/CD to speed up product releases. SRE tries to cut losses with a pipeline.

Site reliability engineering practice complements DevOps and helps a development team to better control the operation of a system. Likewise, a business doesn’t just benefit from getting an app to production faster. It also doesn’t lose a lot of money due to spontaneous failures. So, it’s less productive to look at the issues as SRE vs DevOps as they work together.


SRE ensures that the software that DevOps teams create is available to users when they need it. With these practices, businesses prevent app crashes. It is much more efficient than responding to crashes that provoke user dissatisfaction and affect the budget.

Companies strive to create a reliable product without delaying its release into production. They achieve this by combining the capabilities of SRE and DevOps rather than viewing them as SRE vs DevOps.