Feature Rollout ER Diagram Template

A Feature Rollout ER Diagram captures the data relationships that govern how a software feature progresses from internal testing through beta access, percentage-based rollout, and finally general availability (GA). The entities typically modeled include Feature, RolloutStage, UserSegment, FlagConfiguration, and AuditLog, along with the relationships that connect them—such as which user segments are eligible at each stage, what percentage thresholds trigger promotion, and which flag configurations are active at any given time. By visualizing these relationships in an entity-relationship diagram, teams gain a shared, unambiguous reference for how their feature flag data model is structured and how rollout decisions flow through the system.

## When to Use This Template

This template is most valuable during the design phase of a feature flag or experimentation platform, when engineers need to align on the database schema before writing a single line of code. It is equally useful during incident reviews, when understanding the relationships between flag states and user segments can help pinpoint why a rollout behaved unexpectedly. Product managers benefit from reviewing the diagram alongside engineering to confirm that business rules—such as "beta users must opt in before receiving a percent rollout"—are accurately reflected in the data model. Teams adopting a phased rollout strategy for the first time will find the template especially helpful for identifying entities they may have overlooked, such as override rules or kill-switch configurations.

## Common Mistakes to Avoid

One frequent error is conflating the RolloutStage entity with a simple status field on the Feature entity. Keeping stages as a separate, related entity allows for richer metadata—such as start dates, approval owners, and rollback thresholds—without bloating the core Feature table. Another mistake is omitting the AuditLog relationship entirely; without it, the diagram fails to represent accountability and change history, which are critical for compliance and debugging. Teams also tend to underspecify the UserSegment entity, leaving out attributes like cohort size or eligibility criteria, which makes the diagram less useful for capacity planning. Finally, avoid drawing cardinality incorrectly: a single Feature can exist in multiple RolloutStages over time, and a single RolloutStage can apply to multiple UserSegments, so many-to-many relationships should be explicitly modeled with junction entities rather than implied.