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Project 10: Payment Integration Platform

Phase 3: Advanced Integration
Why This Project?

Payment processing is a high-value skill. E-commerce, SaaS platforms, marketplaces - they all need developers who can handle payments safely and correctly.

This project teaches you how to integrate with third-party APIs like Stripe. You'll learn about webhooks, which let Stripe notify your server when events happen (payment succeeded, subscription canceled, etc).

Security and reliability are critical with payments. You'll learn how to verify webhook signatures, handle failed payments, and keep financial data safe. These skills directly impact business revenue.

Why This Project?

Payment integration is a valuable skill. E-commerce, SaaS products, and many apps need to accept payments. Companies want developers who can handle this safely and correctly.

This project teaches you how to work with third-party services like Stripe. You'll learn about webhooks, which let Stripe notify your app when events happen (payment succeeded, subscription canceled, etc).

Security is crucial with payments. You'll learn to verify webhooks, handle edge cases, and never store sensitive payment data yourself. These practices keep your users safe.

Overview

Implement a complete payment flow with Stripe, handling webhooks, refunds, subscription management, and transaction history. This project teaches you how to safely integrate third-party payment processors and handle financial transactions.

Core Requirements

One-time payment processing with Stripe

Subscription creation and management

Webhook handling for payment events

Refund processing

Transaction history and receipts

Payment method storage

Invoice generation

Failed payment handling

Currency conversion support

Learning Objectives

Integrate Stripe payment processing

Handle webhook events securely

Manage subscription billing cycles

Process refunds and disputes

Store payment data securely

Handle edge cases in payment flows

Payment Features

Checkout page with Stripe Elements

Save card for future purchases

Support multiple payment methods

3D Secure authentication

Automatic retry for failed payments

Email receipts after successful payment

Admin panel to view all transactions

Subscription upgrade/downgrade

Technical Challenges

Verify webhook signatures to prevent fraud

Handle idempotency for duplicate requests

Implement proper error handling for payment failures

Store Stripe customer IDs securely

Handle subscription cancellation timing

Implement proper logging for financial transactions

Test payment flows in Stripe test mode

Helpful Resources

Stripe Documentation: stripe.com/docs has excellent guides. Start with "Accept a payment" tutorial.

Stripe Testing: Stripe provides test card numbers. Use them to test all scenarios.

Webhooks: Read Stripe's webhook guide. Learn how to verify webhook signatures.

Idempotency: Search for "idempotent requests" to handle duplicate submissions safely.

PCI Compliance: Learn basic PCI compliance rules. Never store full card numbers.

Subscription Management: Stripe docs on subscriptions cover billing cycles and cancellations.

Helpful Resources

Stripe Docs: Stripe documentation is excellent. Start with "Accept a payment" guide.

Stripe Testing: Stripe provides test card numbers. Use them to test all scenarios.

Webhooks: Read Stripe's webhook guide. Learn how to verify webhook signatures.

Stripe Elements: Pre-built UI components for collecting payment info securely.

Idempotency: Search for "API idempotency" to learn how to prevent duplicate charges.

Subscription Billing: Stripe subscription docs explain billing cycles and proration.

Success Criteria

Payments process successfully in test mode

Webhooks update database correctly

Refunds reflect in transaction history

Subscriptions renew automatically

Failed payments trigger retry logic

All transactions are logged properly

Hint: Use Stripe's test mode extensively. Test every edge case: successful payments, failed cards, disputed charges, subscription cancellations. Stripe provides test card numbers for all these scenarios.

Submit Your Project

Once you've completed this project, submit your GitHub repository link below: