What is SRE

The stable functioning of large-scale projects or websites depends on many factors and coordinated teamwork. By default, people expect a site to be available at all times, as disruptions can seriously damage a company’s reputation.


Site Reliability Engineering (SRE) is a set of tools and practices that can be used to minimize disruptions and ensure rapid recovery, stability, and smooth operation of a complex system when scaling a project. All this ensures good productivity and, consequently, satisfied customers.


The concept of SRE was developed by Google in 2003 to manage large, complex platforms and search systems. In this article, you will learn what is site reliability engineering and explore the most effective practices of this method, which will help you ensure reliable site performance and recover quickly after incidents.

Ten key principles of SRE

SRE is a set of practices, principles, and methods aimed at creating reliable, flexible, and easily scalable software systems. Below, we cover the key techniques and tools of this culture.


1. Business process interoperability

One of the main goals of SRE is to connect teams and make them work together. It is important for the manager to keep in mind that every innovation or decision will influence everyone involved in the business processes. Therefore, when implementing new methods, connecting new functions, or updating software, consider in advance how it will affect the entire team’s work and discuss your ideas with the specialists involved in these processes. This will help to avoid undesirable outcomes and maximally prepare employees for the new conditions.

2. Automation

Usually, developing or updating software means making many backups, each of which must be tested. In large-scale projects, this process takes a lot of time if testing is done manually. Such organization of the process reduces the efficiency and speed of development. That is why one of the SRE principles is maximum automation. It allows you to transfer routine and repetitive tasks to machines and programs. This will enable you to:


  • reduce the possibility of errors
  • free up specialists’ time for tasks that require creativity
  • reduce labor costs


Automation will also help you optimize deployment and make it continuous. The fact is that every resource has a certain error budget — the time during which the resource can be idle without being penalized. If the company has exhausted that time, SRE engineers must pause the deployment. Automation (by speeding up development and reducing labor costs) allows you to launch the deployment again and make the system more stable.

3. Retrospective analysis

If you create something new (as you know, software is always a unique product), incidents and bugs are inevitable. Don’t be frustrated when they occur, but instead benefit from them. That’s where retrospective analysis can help.


SRE engineers study the history of bugs, identifying the causes in each specific incident. This helps you understand what led to the failure and correct the problem so you don’t repeat the same mistake in the future. This is how you address weaknesses in the system and make it more reliable.


Looking more broadly, retrospective analysis is a great tool for timely recognition of what’s wrong with your strategy. Once you realize this, you will save time and resources by adjusting your path and aligning it more precisely with the project goals.

4. Keeping user interests in mind

The goal of any project is to create a product that the end user will like, which signifies success. Therefore, when developing software, it is important to understand how it will work on the user side. Will the program be user-friendly and intuitive? And will users like the interface? Or will they have trouble accessing certain functions?


Look at your product through the eyes of the user and consider aspects that may be important to them. If possible, obtain feedback from end users, as this will help you understand how the product can be improved.

5. Reliance on data

SRE culture relies solely on objective data and specific metrics. When planning business processes and implementing new tools, you are essentially experimenting, as you don’t know in advance how it will work in your project. SRE collects significant amounts of various data, which can be analyzed to answer the following questions:


  • Are your decisions bringing the project closer to achieving the business goals?
  • Does the chosen path lead to a dead end?
  • What can be optimized and improved to make the system work more efficiently?
  • How can you make the system more reliable?
  • How can you avoid risks and save time and resources in the early stages of development?

6. Invest in effective solutions

SRE engineers analyze the state of the system and ensure its reliability. They know the system peculiarities well and can predict which tools will handle your project’s tasks and increase its efficiency over time.


Encourage specialists to show initiative: let them know you are interested in their opinion. Some tools may cost the company more at the initial stage, but they may bring significant benefits in the long run. Ask engineers to inform you about such opportunities: let them argue their proposal and present you with all its potential benefits.


Try not to stop immediately: be forward-thinking and plan with a long-term perspective in mind. In addition to the immediate benefits to the project, this approach will give you more trust and respect from your colleagues.

7. Service-level objective (SLO)

To understand that the system is working effectively and clients are getting the right level of service, you need to have clear and precise criteria for these concepts. Otherwise, you cannot correctly assess the system’s performance.


Such criteria are provided by SLO — an agreement on specific indicators, which allows all participants of the production process to equally understand its goals, system efficiency criteria, and quality of service.


SLO goals should be:


  • harmonized with business objectives
  • measurable
  • clear and well-defined
  • trackable and analyzable
  • focused on the needs of system users
  • realistic and achievable


With SLO, a manufacturer can continually improve service quality. This practice provides teams with comprehensive data to understand if the company is getting closer to business goals or if the desired progress is not being made. Such information makes it possible to keep a constant finger on the pulse, allowing for timely implementation of any necessary changes in business processes and adjusting them according to the overall objectives of the strategy.

8. Constant building of skills

SRE tools and techniques are not one static set that will remain the same from the beginning to the end of your project. Firstly, technology is constantly developing, with new, more effective technologies replacing the ones you are already familiar with. Secondly, the tasks and goals of your project may change, which could require different tools and skills of SRE specialists.


Therefore, the manager must ensure in advance that employees are ready to receive new knowledge and learn. Encourage the specialists to improve their skills: it will benefit both them and your project.

9. Monitoring

This is the process of constant observation of a system, program, or application. Monitoring data allows you to identify incorrect configurations and other potential problems of each component individually and during their interaction. In this way, you can improve the reliability and efficiency of the system without waiting for problems to manifest, when solving them will require more time and investment.


To ensure effective monitoring, we recommend using the following strategy when considering SRE monitoring tools:


Choose metrics. Determine which metrics you will track to assess the efficiency of the system. For example, these could be response times, error rates, and throughput.


Decide on monitoring tools. We recommend paying attention to the availability and usefulness of the tools, their ability to interact with others, and their ability to be scaled with your project.


Instrument the system. Once you have chosen the right tools for your project, you need to customize the system to interact with them easily; in other words, add code to the system to perform monitoring. This process is called instrumentation.


Visualize the indicators: it is important to design the monitoring results in a way that is clear, user-friendly, and easy to work with.


Use distributed tracing. This method allows you to collect data from all logs and metrics from different services in a single document. This way, you can get an overview of how requests are being executed and detect weaknesses in the system.


Set up alerts: the system will notify you of any current serious problems. This will allow you to take appropriate actions and maintain system stability promptly.
Use end-to-end monitoring: this method allows you to check how well the system works from the end user’s point of view. If you want people to use your product, you must ensure they are comfortable interacting with it. Two methods will help you with this:


  • Synthetic monitoring, which allows you to identify system problems before they become visible to users.
  • Real-time monitoring, which is a tool you can use to assess how users interact with the system in real-time.

10. SRE as a service

If you aren’t currently able to train someone from your team in SRE techniques, you can use the services of an experienced site reliability engineer. DevOps as a service allows you to save time and, with the help of qualified experts, quickly develop a personalized strategy for your project, identify its strengths and weaknesses, determine the most appropriate tools and techniques for it, and increase its efficiency.


Usually, development and operation teams work almost independently, each solving their own tasks. This slows down and complicates business processes, and because of this, the software does not work at its full capacity. Practice SRE aims to maximize team unity, enhance cooperation, and ensure reliable system operation. Systematic implementation of SRE methods makes the system productive, ensuring its fast operation and recovery after incidents in the shortest possible time. Analyzing errors helps to avoid their recurrence in the future and significantly enhances the project’s capabilities. To start using SRE practices in a project, you can train your own employees or contact a company specializing in such services.