Prompt

Implement a feature flag system in my application.

<current_deployment>
{describe deployment process}
</current_deployment>

<use_cases>
{planned feature flag uses}
</use_cases>

<tech_stack>
{current technology stack}
</tech_stack>

Design:
1. Flag storage and management
2. Client-side implementation
3. Server-side implementation
4. Flag evaluation logic
5. Gradual rollout strategies
6. Cleanup procedures