Site Reliability Engineering (SRE) vs. DevOps: Focus, Differences, Similarities, and Practices

On average, downtime costs businesses anywhere between $100,000 to $5 million PER HOUR. This includes the loss of revenues, goodwill, wasted labor on troubleshooting, and business cost of lost productivity.

However, downtime is not the only D-word in the IT industry. Delays in rolling out new features, bug fixes, vulnerability fixes, enhancements, and so on, can drive the customers to the competition. Naturally, IT teams are under extraordinary pressure to minimize downtime and delays in delivering IT services to their users. Site Reliability Engineering (SRE) and DevOps emerged as organic and natural solutions to this challenge.

Both Site Reliability Engineering (SRE) and DevOps concepts focus on accelerating the IT team’s speed, responsiveness, and reliability when responding to external challenges. These challenges can be industry competition, system downtime, system errors, changing user needs and behaviors, or rapid demand growth. SRE and DevOps enable IT teams to respond to these challenges faster by dissolving the natural friction between the development and deployment teams.

SRE and DevOps often work hand-in-hand. In fact, they overlap with each other so well that they are often interchangeable in some settings. However, they are two significantly different concepts with considerable similarities. This article explains the critical similarities and differences between SRE and DevOps, and explores the importance and relevance of SRE.

Let’s begin.

What is Site Reliability Engineering (SRE)?

Site Reliability Engineering (SRE) is a set of practices that apply software engineering knowledge and principles to IT operations to create highly scalable, available, and reliable software systems.

In essence, site reliability engineers are skilled software engineers specializing in keeping things working in an IT environment. They typically spend half their time performing IT operations and system admin tasks manually and the other half of their time automating these tasks. SRE teams’ routine tasks include analysis of logs, incidence response, testing production environments, performance tuning, patch management, and so on.

Ultimately, site reliability engineers are responsible for the availability, latency, performance, efficiency, change management, monitoring, emergency response, and capacity planning of their IT service.

Over time, their objective is to spend less time on their manual tasks, and more time on automating them for improved reliability and responsiveness.

What is DevOps?

DevOps, the union of ‘development’ and ‘operations,’ is a mindset and a culture of collaboration between hitherto siloed departments like development, operations, QA, and security. It combines people, process, and technology to continually provide value to users.

DevOps teams are focused on developing better products faster and making them more reliable to users. By cultivating a DevOps mindset, teams gain the ability to respond to consumer needs faster, roll out new features and improvements quicker, and increase user confidence in their products or services.

DevOps enables businesses to respond to market challenges faster and better in a world of cutthroat competition and unforgiving consumers.

SRE vs. DevOps: How Are They Different?

Now that you understand the basics of SRE and DevOps, and understand how similar they are in their approach, let’s appreciate the differences between them, and how they translate into real-life practices.

1. Implementation

DevOps is an organizational mindset and culture. Its practices are neither standardized nor well-defined and are more abstract than solid. This leaves its implementation to the organization, which can customize their DevOps strategy to suit their organization’s unique context.

SRE, on the other hand, takes a more explicit approach. Its practices are well-defined, and it uses standard metrics to measure and achieve reliability objectives. SRE teams use their knowledge of software engineering and operations data to help development and operations teams to define service level objectives and the metrics to measure them. Then, they work towards realizing those objectives by continuously measuring them.

2. Ownership

DevOps teams identify issues and forward them to the development teams to solve them. Conversely, SRE teams not only identify the issues but also solve them. They have complete ownership of their IT environment — its deployment, issue resolution, uptime, and other aspects.

The same SRE team is responsible for deploying, monitoring, and maintaining the code. The underlying philosophy is to reduce the transaction time between development teams and the QA or deployment teams. Naturally, site reliability engineers must have strong coding knowledge, complemented by an operations mindset.

3. Role

DevOps plays the role of a connecting link between the development and operations team. They align the objectives of the two teams and focus their attention and efforts on the continuous delivery of value to users.

However, SRE takes a more head-on approach to realize business agility. It takes complete ownership of deploying, monitoring, and maintaining the code. Instead of forwarding the issues to the development team, or relying on the operations team to raise availability issues, they perform both sets of tasks manually as well as automate those tasks. SLOs, like the availability of IT services, begin and end at SREs.

Why We Need Site Reliability Engineering?

SRE and DevOps have many overlapping objectives. They both bring down organizational siloes; they anticipate and proactively address system failures; they emphasize gradual change over transformational changes. Despite their shared goals, SRE offers some specific benefits that DevOps generally doesn’t.

The abstract nature of DevOps doesn’t always align with the SRE process. The DevOps structure or process depends significantly on the “change agent” who is responsible for implementing DevOps in the organization. For these reasons, here are some of the common benefits SRE offers that DevOps usually (not necessarily) doesn’t:

1. Boosts Reliability

IT system failures can quickly escalate into major disruptions, which affect the quality of service, brand reputation, and business revenue. SRE teams drastically bring down the time delay between issue identification and issue resolution. This improves the reliability and uptime of the IT services, thereby ensuring a smooth user experience.

2. Prioritizes Mission-critical Tasks

While DevOps takes a more agile approach to responding to external challenges, it doesn’t offer a strategy for prioritizing the tasks. Here are some questions DevOps doesn’t bother with:

· Do we fix a bug in the UI, or do we fix a bug that intermittently requires the backend app to be restarted?

· Do we add a great new feature, or do we automate backups?

· Do we improve an app’s performance, or do we reduce its mean time to recovery (MTTR)?

· Do we improve deployment automation, or do we improve standards compliance?

SRE answers these questions and brings clarity to all the stakeholders. In fact, SRE gets all stakeholders to talk about the mission-critical tasks and prioritizes them. In the process, it ensures everyone is working on problem-solving with complete awareness of what others are doing and how it fits into their work (e.g., dependencies).

3. Data-driven Decisions

SRE relies on metrics to continuously track and monitor the critical performance of IT systems. Site reliability engineers have outstanding analytical skills, which they use to extract sharp insights from the metrics. Then utilize this data to make decisions that improve the reliability of the IT systems.

4. Rapid Recovery

Despite extensive planning and preparation, system failures are inevitable. When they manifest, site reliability engineers minimize the disruption to the users by quickly identifying and resolving the issue.

Site reliability engineers also use automation to reduce or even eliminate human errors across the IT environment. The separation of the human element from the IT systems makes the latter more robust against failures and accelerates the decision-making process when it comes to deployment.

5. Resource Provisioning

The continuous monitoring of IT system performance allows SRE teams to anticipate, identify, and respond to demand fluctuations. When the demand shoots up, site reliability engineers can provision additional resources, and once the demand drops to normal levels, they can optimize the resources. In effect, SRE makes IT systems highly scalable.

6. Proactive Response

Seasoned site reliability engineers can identify customer-facing issues even before the customer has had a chance to report them to the support team. The same goes for IT security; they can detect security threats before they have had the opportunity to wreak havoc on the systems.

By raising alarms on issues before they blow up into disasters, site reliability engineers protect businesses from potential backlash.

SRE Best Practices

SRE achieves its objectives by following these 5 best practices:

· Measure availability, uptime, outages, toil, and other performance metrics of the IT systems

· Both the developers and operations team use the same tools and technologies to improve collaboration, coordination, and prioritization

· New releases are equipped with the formula (automation features) for containing & balancing failures in new releases

· Minimizing manual work for long term value addition

· Fail early and move ahead quickly to reduce the cost of failure


DevOps and SRE complement each other in most IT setups. However, in some organizations, one of them could be more relevant than the other. Which strategy suits your organization best depends on your industry, customers, competition, product, and business goals.

Field CTO | Technology Visionary | Customer Champion | Big Thinker.