CircleCI is an enterprise CI/CD platform used by engineering teams to build, test, and deploy software at scale. Thousands of organizations rely on CircleCI to run workflows on every commit across large codebases and complex pipelines. Developer notifications are critical to how teams understand build outcomes, respond to failures, and keep work moving across the organization.

Over time, CircleCI’s notification infrastructure evolved across multiple internal systems. Several generations of notification logic existed in parallel, each responsible for different parts of the same workflows. Ownership was unclear, behavior was inconsistent, and it became difficult to evolve notifications without increasing complexity.

Product notifications were tightly coupled to version control systems such as GitHub, GitLab, and Bitbucket, which manage source code and track events like commits and pull requests. These low level events did not always reflect what developers actually cared about, such as whether a build failed, which job caused the failure, or whether action was required.

Notification logic lived directly in application code, and delivery was largely limited to email. Adding new notification types, reducing noise, or supporting channels like Slack required significant engineering effort. As CircleCI continued to scale its enterprise CI/CD platform, fragmented systems made it difficult to support new workflows and deliver clear, actionable developer notifications.