Subscription Management System

Design a comprehensive subscription management system that supports all standard subscription functionalities.

Requirements:

• Create and manage subscription plans (monthly, yearly, lifetime)
• Handle user subscriptions and renewals
• Process payments and handle failures
• Support trial periods
• Manage cancellations and refunds
• Handle upgrades/downgrades between plans

Key Components:

• Plan Service: Define subscription tiers and pricing
• Subscription Service: Manage user subscriptions
• Payment Service: Process recurring payments
• Notification Service: Payment reminders, expiration notices
• Analytics Service: Subscription metrics

Discussion Points:

1. How do you handle payment retry logic for failed transactions?
2. How do you handle proration for plan changes?
3. What grace periods exist after payment failure?
4. How do you integrate with payment providers via webhooks?
5. How do you handle timezone differences for billing?

Scale Considerations:

• Millions of active subscriptions
• Daily batch processing for renewals
• Real-time webhook processing
• Global multi-currency support