Unleash 2023: A Year of Transformative Growth – From Unleash 4 to 5

Fireworks and celebrations

Reflecting on 2023, it’s clear that it has been a transformative year for Unleash. We’ve introduced a series of updates and features to bolster collaboration, continue focusing on a great user experience, advance feature flag management, and much more. Let’s walk through the key highlights of what we have built for you and how it has shaped our journey this year.

1. Transition from Unleash 4 to 5

Unleash 4: Unleash 4 had five major releases from version 4.19 to 4.23 in 2023, focused on enhancing existing functionalities, introducing features like change requests, environment-dependent variants, and better API token management, all aimed at improving collaboration and compliance in development workflows. Unleash v4 officially supported Node.js v14 and v16, but both reached end of life in 2023, which was a significant factor in moving to Unleash 5.x

Unleash 5: Unleash 5 is a significant step forward in feature flag management. With a focus on enhancing developer workflows and operational efficiency, Unleash 5 introduces a range of functionalities designed to streamline processes and improve the overall user experience. The upgrade process from 4.x to 5.x is simple and can be accomplished in a few minutes without downtime. Unleash 5 also dropped support for Node.js versions below 18, the current active LTS.

2. Performance and Resilience

In early 2023, we introduced Unleash Edge, the successor to Unleash Proxy. Unleash Edge provides a cached read-only replica of your Unleash instance, meaning you can scale up to thousands of connected SDKs without increasing the number of requests you make to your Unleash instance. Unleash Edge provides significant performance and resilience benefits; a single instance can handle tens to hundreds of thousands of requests per second, and it is designed to survive restarts and operate properly even if you lose connection to your Unleash server. Unleash Edge helps you scale Unleash.

3. Improved Collaboration and Compliance

Unleash 5 incorporates features like change requests and dependent feature flags to facilitate better team coordination. These tools are particularly useful in regulated environments where traceability and synchronization are crucial. Change requests help teams to work more effectively within regulated environments and maintain compliance standards, while dependent feature flags further streamline the release process, especially for complex deployments.

4. Integrations and Ecosystem Compatibility

With improvements in integrations like Slack, Jira Cloud, Terraform, and Datadog, Unleash 5 strengthens its compatibility within the development ecosystem, making it more versatile and adaptable to various workflows. Furthermore, making segments open source in 5.5 significantly reduced vendor lock-in and fostered a more inclusive Unleash community.

5. Continuous Improvements to User Interface and Experience

2023 saw significant enhancements in user interface and experience. The introduction of dark mode and the revamped project overview UI were steps towards a more intuitive and user-friendly interface. We also focused on improving communication within the Unleash Admin UI by implementing banners in 5.7, ensuring clear and effective user communication. Coupled with UI improvements across the platform, these changes aim to enhance usability and reduce visual strain during extended use.

6. Advanced Targeting

A key addition in Unleash 5 is the concept of Strategy Variants, allowing for more granular control and intricate conditions within feature flags. This advancement aids in creating complex feature release strategies with ease. Strategy Variants enable you to benefit from constraints and segments to control variants. For example, it is now possible to implement intricate conditions in tandem with percentage distributions, such as:

  • Serving the ‘titleForInternalUsers’ to a predefined internal user segment.
  • Presenting ‘titleForGmailUsers’ to customers with ‘@gmail.com’ email addresses (utilizing an ‘ends with’ operator).
  • Dividing the remaining users equally between ‘genericTitleA’ and ‘genericTitleB’ (a percentage split).

We’ve done all of this at the strategy level, which improves and simplifies both the developer experience and UI.

7. Operational Efficiency and Troubleshooting

We enhanced operational efficiency and troubleshooting through several updates. The Playground improvements in 5.7 and the Last Seen feature across multiple releases exemplify our commitment to providing tools that simplify operations and enhance problem-solving capabilities.

Additionally, the introduction of Maintenance Mode lets administrators put Unleash into a read-only mode, useful during important events when any accidental or deliberate changes in the feature or strategy configurations could lead to issues.

8. Security and Access Control

Security and access control received significant upgrades, notably with the introduction of root-level access control. This feature provided granular control over permissions, catering especially to the needs of large enterprises.


As we bid farewell to 2023, we are proud of all the value we have created for you with Unleash. Each release has been based on your input and our goal to deliver a feature flagging tool that is not only powerful but also intuitive and user-centric. We are excited to continue this journey together with you and can’t wait to show you what we have in store for 2024.

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