What if your workflow could tell operators exactly what's happening, and let them take action, right from the Cadence Web UI?

With Custom Workflow Controls, now it can.

Hi Cadence Community,

At the beginning of every year, we share about what happened in the last year. Here’s a look back at our 2025 improvements, explaining what’s new, and how you can use them. 2025 was one of the most exciting years for the Cadence project and we hope this will only get better in the future. Here are some highlights:

Help Cadence Reach CNCF Incubation​

Cadence is an open-source workflow orchestration platform. Our community currently includes more than 150 companies and it continues to grow. Many critical services are built with Cadence as it simplifies complex systems by separating business logic from its distributed system concerns.

Recently, Cadence was donated to Cloud Native Computing Foundation (CNCF), which is a major step towards making it an industry standard and receiving support from all around the world. In other words, the Cadence project is now a Linux Foundation project, licensed under Apache v2 which allows anyone to use and extend it freely. The project operates with open, merit-based governance, giving everyone the opportunity to help shape its future.

See Start Workflow in Action​

For a long time, controlling Cadence workflows was primarily done through the client SDKs or the administrative CLI. Our vision for Cadence Web has been to evolve it from a read-only inspection tool into a Unified Operational Hub for all workflow management needs. This means putting every essential workflow action directly in the hands of operators, support engineers, and developers—right where they observe workflows.

Over the past releases, we’ve been steadily introducing interactive capabilities such as Terminate, Cancel, Restart, Signal, and Reset. Each of these brought Cadence Web closer to becoming a full-featured operational console.

We’re proud to announce that the Cadence project has joined the CNCF (Cloud Native Computing Foundation)®, the open-source foundation that hosts and maintains critical components of modern cloud-native infrastructure including Kubernetes®, Prometheus®, and Envoy® under the Linux Foundation®.

Are you struggling with uncontrolled concurrency when trying to process thousands of activities or child workflows? Do you find yourself hitting rate limits or overwhelming downstream services when running bulk operations? We've got great news for you!

Today, we're thrilled to announce Batch Future, a powerful new feature in the Cadence Go client that provides controlled concurrency for bulk operations. You can now process multiple activities in parallel while maintaining precise control over how many run simultaneously.

Cadence users, especially new users, often struggle with failed/stuck workflows and are unable to understand what is wrong with their workflow. This can now be addressed by a tool that runs on demand to check the workflow and provide diagnostics with actionable information via clear runbooks that users can follow. The overarching goal is to help cadence users understand what is wrong with their workflow

At Uber, we manage billions of workflows with lifetimes ranging from seconds to years. Over the course of their lifetime, workflow code logic often requires changes. To prevent non-deterministic errors that changes may cause, Cadence offers a Versioning feature. However, the feature's usage is limited because changes are only backward-compatible, but not forward-compatible. This makes potential rollbacks or workflow execution rescheduling unsafe.

To address these issues, we have made recent enhancements to the Versioning API, enabling the safe deployment of versioned workflows by separating code changes from the activation of new logic.

At Uber, we previously relied on a dynamic configuration service to manually control the number of partitions for scalable tasklists. This configuration approach introduced several operational challenges:

• Error-prone: Manual updates and deployments were required.
• Unresponsive: Adjustments were typically reactive, often triggered by customer reports or observed backlogs.
• Irreversible: Once increased, the number of partitions was rarely decreased due to the complexity of the two-phase process, especially when anticipating future traffic spikes.

To address these issues, we introduced a new component in the Cadence Matching service: Adaptive Tasklist Scaler. This component dynamically monitors tasklist traffic and adjusts partition counts automatically. Since its rollout, we've seen a significant reduction in incidents and operational overhead caused by misconfigured tasklists.

We are excited to announce the release of cadence-web v4.0.0—a complete rewrite of the Cadence web app. Cadence has always been about empowering developers to manage complex workflows, and with this release, we not only modernize the web interface by embracing today’s cutting-edge technologies but also strengthen the open source community by aligning our tools with the broader trends seen across the industry.

What's new in cadence-web v4.0.0​

• Revamped UI & Experience – A fresh, modern interface designed for better usability and efficiency.
• Multi-Cluster Support – The UI can now connect to multiple Cadence clusters.
• Performance Improvements – Faster load times, optimised API calls, and a smoother experience.