Continuous delivery and deployment are two widely used software engineering approaches today.
They aim to scale delivery and accuracy in implementing software changes, updates, or improvements.
While these two processes work hand in hand as part of the continuous software delivery pipeline, they have different goals and scopes.
In this continuous delivery vs deployment comparison, we’ll dig deeper into their significant differences and how they work together to help you build a solid software product that your customers will love.
What is Continuous Delivery?
Continuous delivery is a software engineering approach to safely, quickly, and sustainably implementing all types of software changes.
These changes include configurations, updates, feature releases, bug fixes, and experiments.
The goal of continuous delivery is to make deployments, whether simple or complex, predictable and on-demand.
Why Is Continuous Delivery Important?
Before launching any software, a lot of processes and modifications take place.
Various teams working on different modules need to work together to support even minor changes in the program.
Continuous delivery brings all testing steps and deployments together to get changes into production safely.
In other words, continuous delivery aims to make software deployments painless and achievable with just a “push of a button.”
Another important role of continuous delivery is to prevent large amounts of re-work needed to deploy changes at the soonest time possible.
It's not uncommon for the integration and testing stages of the traditional software delivery cycle to take several weeks or months.
When teams work to automate the deployment process, the delivery of changes takes place in a significantly shorter period.
There is no one-size-fits-all approach to continuous delivery. Instead, in most industries, there's a wide range of technology choices and platforms that facilitate a successful pipeline delivery.
Here are some of the best practices to consider for effectively automating delivery:
- Automate repetitive processes.
For CD to scale continuously, it's essential to automate every repeatable process throughout the software development, from testing to deployment.
- Eliminate complexity where you can.
Most of the time, automation happens gradually, spreading automation code across several tools. That said, they can become harder to use and monitor.
Thus, it's helpful for teams to streamline their automation processes by keeping all their automation code in one place.
What Is Continuous Deployment?
While continuous delivery focuses on the release and release strategy, continuous deployment focuses on automating the deployment of the software features and functionalities across environments or clusters.
Unlike continuous delivery, which involves human intervention, continuous deployment relies entirely on technology. Thus, all code changes in the software or application are released automatically into production.
Why Is Continuous Deployment Important?
Continuous deployment is a critical phase of software development.
With the rapidly changing demands for new features and improvements, it is crucial to have a fast and seamless process to test and deploy the final release.
Continuous delivery tries to achieve this goal by automating software delivery pipelines.
It is a strategy for implementing the release of milestones without affecting the current software functionality.
Continuous deployment has the following advantages in the software development cycle:
- Implementing more minor code changes is simple and has fewer unintended consequences.
- The product improves quickly through fast feature introduction.
- Critical changes are introduced or deployed during non-critical hours, limiting deployment issues' potential impact.
- Release cycles are shorter.
- Continuous deployment promotes end-user involvement and feedback, which supports usability improvements.
How your team implements a continuous deployment process depends on your needs and dynamics. However, there are a few best practices that are central to successful deployment:
- First, automate the build and deployment.
Similar to continuous delivery, keeping the deployment fast is a worthy goal. Thus, aim to automate things, such as compiling the code or executing unit and integration tests.
- Maintain a central code repository.
DevOps teams usually work on multiple pieces of code at a time. Creating a central repository of codes with a revision control system is an excellent way to avoid messy code builds.
- Clean your environments
It's worth cleaning up your pre-production environments because they can be hard to keep track of later.
Maintaining clean environments can speed up testing and prevent delays in the release process.
- Monitor your pipeline
By monitoring and measuring your pipeline, you can identify potential issues and areas for improvement.
Moreover, tracking the speed of deployments can help you identify when it's best to invest in performance optimizations.
Compare the number of builds you have per hour, day, and week to determine whether you need to scale them up or down during peak loads.
How They Work Together
It's hard to link continuous delivery and deployment without mentioning continuous integration (CI).
CI is the automation of builds. It's a practice where developers merge code changes into a central archive and conduct tests on automated builds.
These changes are then validated by creating a build and conducting automated tests against the build.
CI emphasizes testing automation to ensure the application doesn't encounter errors or bugs whenever new commits integrate into the main branch.
Continuous delivery and deployment are the optimal approaches to automating software development.
Together with continuous integration, they enable DevOps teams to release new features, fixes, and enhancements with incredible speed and accuracy.
Continuous delivery and deployment have a lot in common, but they are two distinct processes. So before considering which of these methods to implement, determine if your DevOps culture can support them.
It's not a matter of which one is better but which addresses the needs of your software development journey.
If you need a manual trigger between continuous integration and delivery, you may implement continuous deployment and automate software delivery from start to finish.
Otherwise, you may start with continuous integration and delivery wherein you automate the creation of production-ready code after a manual approval from deployment.
Either way, you'll gain many advantages, such as creating deployable codes and implementing changes that are automatically validated and tested.
Furthermore, these practices ensure that your releases receive quicker feedback from customers and stakeholders and that your developers are more productive with their time.