System Design: Feedback + Feature Rollout Platform

Context

Build a multi-tenant platform that lets product teams:

• Collect end-user feedback from applications.
• Control feature rollout to targeted cohorts via feature flags.

Assume web/mobile SDKs, admin console, and public APIs. The platform should serve multiple tenants (organizations) and environments (dev/stage/prod).

Requirements

Functional

1. Feedback
   • Submit end-user feedback (text, screenshots, metadata).
   • List/search/filter feedback by tenant, app, environment, tags, status.
   • Moderation workflow (auto + human review).
   • Analytics aggregation (trends, NPS/CSAT, tags/topics).
2. Feature Flags
   • Create/update/delete flags with variants and targeting rules.
   • Evaluate flags in real time with caching for low latency.
   • Gradual rollouts (percentage-based, rule/segment-based).
   • Kill switches and safe defaults.
3. APIs and SDKs
   • Endpoints such as submitFeedback, listFeedback, createFlag, evaluateFlag.
   • Admin console for configuration and moderation.

Non-Functional

• Multi-tenancy isolation, authn/z (RBAC), rate limiting.
• Privacy/PII handling, data residency, encryption.
• Audit logs, safety/observability, SLOs.
• Scalability, cost efficiency, DR/BCP.
• Consistency expectations and propagation SLAs.

Deliverables

• Service boundaries and data flows.
• Core classes/objects and database schemas.
• API endpoints (with request/response fields).
• Handling of multi-tenancy, authn/z, rate limiting, moderation, analytics, PII, caching, rollout strategies, kill switches, audit logs, safety/observability.
• Scaling estimates and consistency considerations.