Why are Feature Flags Important for Your Deployment Strategy?
Tags: frontend, webdev, beginners
Published: 2023-12-21 21:49:21


One of the tasks of being a junior software engineer in my team is to write reusable code that meets the software requirements. Hence, the DevOps team will work on deploying the software and automating the process.

In this post, we’ll look into the deployment strategy and the difference between a conventional and modern method of deployment strategy. We’ll also look at the importance of feature flags in deployment strategies.

Additionally, we’ll also look at feature flags for dark launching, canary release, and new features.

## Understanding Deployment Strategy

What is **Deployment Strategy**? Deployment strategy in IT operations and software development is a set of techniques adopted by DevOps teams. This helps them update and release software applications in a very reliable condition.

In my company's case, systems get delivered without errors with little or no downtime to the end-users.

## The difference between a conventional  and “Modern” method of Deployment Strategies

There are two main known deployment strategies for updating a system and releasing software. They are the traditional method and the modern method of deployment strategies.

### Conventional or Traditional Deployment Strategies.

**Waterfall Model**: This strategy has some characteristics which include but are not limited to sequential phases, comprehensive documentation, and limited flexibility among others. It is not a deployment strategy per se, but a traditional software development approach. Waterfall in the realm of deployment simply means each phase like the development, testing, and quality assurance phases must come before deployment.

**Big-Bang Deployment:** This strategy encompasses all changes, and hence, rolls out all the changes at a go without any incremental updates.

### Modern Method of Deployment Strategies

**Continuous Integration/Continuous Deployment (CI/CD)**:  This is one of the modern methods of deployment. A method where any changes to a code are constantly integrated into a repository by large team members, and subsequently deploy the code changes to production.

**Cloud-based Deployment**: With cloud-based deployment, cloud computing services like Amazon Web Services (AWS), and Google Cloud Platform are used for the implementation of strategies as required by your specific needs.


### Importance of Features Flags in Deployment Strategies

With feature flags, my company software and DevOps teams have total control of specific features on either a website or in a software application.
It reduces the risk of introducing bugs to the software by the software team, by allowing the software team to incrementally release new features, as well as selective releases of the feature to a specific user base.


## Feature Flag in Deployment Strategy as a Risk Mitigation Tool

Having explained both the deployment strategy and the feature flags. Let's now explore why the feature flag serves as a risk mitigator during deployment strategy.

Risk mitigation during deployment strategy is identifying, minimizing, or eliminating risks that are bound to happen. Especially, during software application deployment.

While it’s difficult to identify all issues during deployment. It is a key concept to manage risk for smooth, and seamless deployment.

### Feature flags help to serve as a mitigation tool in several ways

**Measured Rollout**: Risk mitigation is identifying risk before deployment. Feature flags allow you the opportunity to test your new functionality with a controlled subset of users in a limited exposure environment. With this, the impact of issues, if there are any, gets confined to a smaller group of users.

**Flexible Rollback**: Feature flags provide an instant ability to undo a change when critical or unexpected issues occur during development. This flexible rollback enhances customer satisfaction because it minimizes the risk of extended downtime.

## Feature Flags in Deployment Strategy for User Personalization

User personalization in deployment strategy is the process of personalizing software applications to a specific individual user. This is a strategy employed by us to improve user experience and enhance user retention.

### Feature flags help with User Personalization in Several Ways

**Gradual Rollout:** Feature flags help in user personalization by allowing developers to watch the performances of the features gradually released to a distinct set of users. This empowers the developers to increase the testing sample of users with the feature, because of the stability of the feature.

**Instant Rollbacks**: Feature flags allow developers without waiting for the full deployment to revert to the status quo if the newly baked user personalization feature produces an unwanted or unexpected issue that may lead to a bad user experience.

## Feature Flags in Deployment Strategy for Parallel Development

In my team’s example, parallel deployment is the strategy we employed to compare and contrast vital information like functionality, and performance between the previous and the new version of the system application

Parallel deployment also known as parallel development is a software deployment strategy that reduces downtime, risk of failures, and errors. By allowing the gradual transition from the previous version to the new version of the software application.

### Feature flags help for Parallel Development in Several Ways

**Reduction in Merge Conflic**ts: Feature flags help reduce merge conflicts that arise from parallel development. Most especially if there are many developers on a codebase. By enabling a flag, where each developer can work on their features. Feature flags mitigate the issue of merge conflicts.

**Reduction in Time-to-Market**: Feature flags fastrack the time-to-market for new features. This enables the deployment of a feature despite having several developers working on many features before the other parallel efforts are completed.

## Feature Flags in Deployment Strategy for Continuous Integration and Continuous Development (CI/CD)

The integration of code changes into a shared repository, and deployment of the system application is achievable through Continuous Integration and Continuous Development for continuous testing of the software.

### Feature flags help for Continuous Integration and Continuous Development in Several Ways

**Incremental Rollouts:** Feature flags allow for the deployment of features incrementally under a feature flag, to gradually expose the feature to a specific set of users.

**Risk Reduction:** Feature flags help in identifying and addressing issues at the early stage of development. With the bit-by-bit release of the features. This allows for the risk reduction associated with deploying changes at a stretch.

## Feature Flags in Deployment Strategy for Emergency Response

Emergency response is a deployment strategy for combating and addressing unannounced critical situations. This kind of strategy is mostly employed by government agencies and some emergency service providers. Feature flags help the organization to adequately respond to unforeseen circumstances.

### Feature flags help in Deployment Strategy for Emergency Response in Various Ways

**Recovery:** Feature flags help in the recovery process immediately after the response stage. They can reintroduce features as the situation is brought under control, and iterating based on the needs of the respondent.

**Top-Notch Security**: Feature flags allow for prompt disabling of potentially exploitable features. That in turn combats the effect of the attack environment.

## Features Flags for Dark Launching

Dark launching is the process of releasing a specific feature and taking its functionality to a segment of your users. It is also the less exposure of traffic of code deployed to the production environment.

Take my company as an example, dark launching is the release that allows our DevOps teams to fix bugs, access performance metrics, and gather feedback from the user about the feature.

The practical way to use dark launch is through feature flags, that allow the DevOps team to control both the visibility and availability of the new feature without deploying the code.

My team DevOps teams use dark launching to test new features on a segment of their user base. This opportunity is unlike the traditional method of releasing a risky-prone feature.

### Pros of Dark Launching with Feature Flags

**Real-time Control:** Dark launching can start and finish the lifecycle of a feature with the help of a feature flag. 

**Continuous Deployment**: Dark launching separates feature release from feature development with continuous deployment. It is easy to test new and existing features concurrently without disrupting the user experience.

## Features Flags for Canary Release

Canary release is a release strategy employed for testing a newer version of an application in a real-world environment to gather feedback before making it available to a wider section of users. 
Our  DevOps team tests the feature stability by setting up the updated feature and shifting the production traffic from the old version of the feature to the updated features.

### Feature Flags with Canary Release

Feature flags help in implementing canary release with its value set to off, this ensures no users have access to the new feature.
With a feature management platform like Unleash, the feature flags test the new features with a small percentage of users. The team can include beta testers or internal teams.
Proper monitoring of the performance metrics and feedback from the release, and an instant turn-off of the feature flags if issues are detected.

### Pros of Canary Release with Feature Flags

**Quick Iteration:** Feature flags with the help of performance metrics, and feedback from users enable quick adjustments to the software application.
**A/B Testing:** Feature flags helps in comparing the performance and user engagement of distinct feature variation. This process is known as the A/B testing.

## Features Flags for New Features

New features are an innovative approach to improve the speed, flexibility, and efficiency of software deployments. It is a new innovative approach or methodology that enhances the software deploying process.  

New features require meticulous planning and execution for any organization that hopes to deliver high-quality software to its users while maintaining the ability to adapt to business needs.

### Pros of New Feature with Feature Flags

**Speed**: Feature flags help the new feature to be fast in improving the software deployments.

**Flexibility:** Feature flags enable the new feature to be flexible which enhances the software development.

## Conclusion

So, now you understand deployment strategy and the difference between traditional and modern methods of deployment. We have also discussed the importance of feature flags in deployment strategies, as well as the feature flags for dark launching, canary release, and new features.