The Definitive Guide to CI, CD, & CDE

The Agile methodology


Iterative Methodologies vs Waterfall

Why do I care?

What is Continuous Integration (CI)?

How it works

Continuous Integration (CI)

Key Strengths of Continuous Integration (CI)

  1. Testing
    It’s no secret that testing the same test scripts every day can be a highly monotonous duty. Most development teams have found that the automation of test scripts wherever possible goes a long way. Not to mention, it also provides immediate feedback to the developer in mere minutes.
  2. Issue Resolution
    When the automated test scripts do find an issue in the code, because the code segments are small, the developers have been able to make quick work of issue identification and resolution.
  3. Phased Changeover
    With small iterative changes, studies have confirmed that the migration from an old version of the software to a newer version is much easier because the users are eased into the changes, instead of having to learn a new version of the software all at once.
  4. Improved Team Morale
    Surprisingly, submitting these iterative changes has also improved dev team morale, especially when tasked on larger projects. The reason is that it’s part of our human nature that we like to see accomplishments regularly. Unlike the waterfall methodology, where a large project can drag on for weeks or even months without completing any key milestones, the iterative approach allows developers to achieve multiple milestones per day. This also provides the immediate gratification of seeing their code passing the automated tests several times a day.
  5. Increased Velocity
    Teams have found that with the iterative changes to the code, automated builds, automated testing, and the rapid identification of issues, the overall velocity of the project delivery is significantly faster in comparison to waterfall methodology.
  6. Improved Quality
    Because issues are found and resolved with each sprint, those larger, more comprehensive development issues are substantially mitigated. This is because once a sprint has been deployed, subsequent code iterations are then added to the code that has already been proven to be functionally correct. This eliminates the issue of needing to fix multiple incorrectly developed modules because of a coding issue in a single module.
  7. Improved Budget
    With the increase in delivery velocity and shifting the identification and resolution of coding issues left, teams are saving a lot of time and resources, which all add up to a healthier bottom line.

What is Continuous Delivery (CD)?

Continuous Delivery (CD)

  1. Improved Velocity
    The delivery speeds are notably faster due to the addition of the automated release into the staging/test environment. If your team also automates the system tests, it makes the overall delivery that much faster.
  2. Phased Progression
    Like Agile and CI, small segments of code are iteratively added to the mainline throughout the day. As the new code is added throughout the day, the mainline application evolves step by step to the target state.
  3. Always Production Ready
    With this methodology, the product version that sits in the staging or simulated production environment is always in a fully production-ready deployable state. This allows it to double checked, or to be held until other features are added and enabled. The advantage is that it is always ready and can be released into production at the push of a button. This methodology gives your leadership total control over product delivery.
  4. Release Control
    With a product that’s always production ready, the deployment to production becomes a business decision, providing total control over the user experience.
  5. Additional Testing
    This model allows the production-ready product to undergo additional, more comprehensive testing in various test environments, including integration testing, system integration testing (SIT), User Acceptance Tests (UAT), load testing, performance testing, and any others that your organization may require.

What is Continuous Deployment (CD)?

Continuous Deployment (CD)

  1. Morphed Migration
    The product gets built iteratively in production and more or less morphs from one version to the next. This approach substantially reduces the anxiety that customers have when they are given a whole new version of the software that they now have to learn.
  2. Enhanced Delivery Velocity
    Gone are the days of creating code and lobbing it over the fence to builders, who then bounce it to the testers and so on. With continuous deployment, the developer can check code and get a pass/fail notification within minutes. If an issue is detected, they can resolve it and have the new version submitted and into production within a few minutes. If no issues are detected, the new code is moved automatically into production.
  3. Shift Left
    When a developer checks in code, the automated processes take the code and move it through the entire lifecycle and if it passes each gate, it gets deployed directly to production. This provides the developer with nearly immediate feedback regarding if a code segment has a defect or not. If an issue is detected in the automated tests, the developer is notified and can resolve the issue immediately.
  4. Expedited Tests
    Testing has traditionally been a bottleneck in the development lifecycle. However, with CD, automated tests can be set up throughout the value stream to be as thorough as needed. This means the testing can be set up at the appropriate stages to address the progression of the code throughout the lifecycle. This can include automated unit tests, integration tests, regression tests, performance tests, and so forth. These can be set up and executed at their respective stations in the lifecycle providing a thorough testing framework to ensure quality. However, because the gate management and handoff from one state to the next are also fully automated, the progression of the code through the lifecycle occurs at light speed when compared to the legacy waterfall approach.
  5. Real World Experimentation
    This model also allows for real-world experimentation, such as A/B testing, and allows for immediate consumer feedback. For example, if you need to change the location of a certain feature on a website, but you’re not sure of the best new location, you could make the change, monitor real-time customer usage, and make adjustments accordingly.

What are the challenges?

Click here to read the rest of the article on our blog.



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