Feature Rollout Class Diagram Template

A feature rollout class diagram models the relationships between the core entities that govern how a feature progresses from an internal build to general availability. The diagram typically includes classes such as `Feature`, `RolloutStage`, `UserSegment`, `RolloutPolicy`, and `FeatureFlag`, along with their attributes and associations. For example, a `RolloutStage` class might hold properties like `stageName` (internal, beta, percent, GA), `targetPercentage`, and `startDate`, while a `FeatureFlag` class tracks `isEnabled` and `overrideRules`. By visualizing these relationships, teams gain a shared understanding of how the system decides which users see a feature at any given moment.

## When to Use This Template

This template is most valuable during the design phase of a feature flag or progressive delivery system. Engineering leads can use it to align backend developers on data models before implementation begins. Product managers benefit from seeing how rollout policies connect to user segments, making it easier to communicate rollout logic to stakeholders without diving into code. It is also useful when onboarding new engineers to an existing rollout infrastructure, since the diagram provides a high-level map of how classes interact across stages.

## Common Mistakes to Avoid

One frequent error is conflating rollout stages with deployment environments. A class diagram for feature rollout should represent logical progression states—not infrastructure layers like staging or production servers. Keep `RolloutStage` focused on audience targeting logic. Another mistake is over-engineering the diagram by adding every attribute from the database schema. Stick to the attributes that drive rollout decisions, such as eligibility rules and percentage thresholds, and omit implementation details like primary keys or audit timestamps. Finally, avoid missing the relationship between `UserSegment` and `RolloutPolicy`; this association is the heart of percent-based and beta rollouts, and leaving it out makes the diagram misleading. A clean, well-scoped class diagram accelerates team alignment and reduces costly misunderstandings during feature delivery.