Portfolio Assignment: This Assignment Will Serve As The Port

Portfolio Assignmentthis Assignment Will Serve As The Portfolio Assig

This assignment will serve as the "Portfolio Assignment" for this course. A portfolio assignment is an applied task that showcases your ability to apply the knowledge gained during the course. You are encouraged to create a free DU portfolio to store evidence of your learning, such as papers, projects, and key course assignments, throughout your coursework at University College. Sharing this portfolio with potential employers or colleagues can demonstrate your skills and progress. Maintaining a portfolio allows for reflection, contextualization of your work, and continuous improvement as you develop your skills over time.

For this specific assignment, you will compile all your work from previous assignments related to a simplified payment processing system into a coherent, high-level design. You may use previous work verbatim where appropriate, incorporating any feedback received. Your final submission should include the high-level design and relevant code snippets organized coherently, either embedded within your document or in a structured package that can be submitted as a zip file.

Paper For Above instruction

Designing a simplified online payment processing system is an instructive task that combines understanding of payment workflows, system architecture, and software design principles. The objective is to develop a high-level architecture that encapsulates all core components, interactions, and communication protocols necessary for a functional and scalable payment system that handles credit card transactions. This system would be illustrative of key concepts in payment processing, system design, and integration with external credit card companies.

Introduction

The payment processing system under consideration is designed to manage online credit card transactions efficiently, securely, and reliably. It is structured to simulate real-world payment workflows, including authorization, batching, and settlement. At its core, the system interacts with an external credit card processor to perform authorization requests in real-time and batch payment requests for settlement. The architecture emphasizes modularity, scalability, and security to ensure it can adapt to increasing transaction loads and evolving security standards.

Requirements

  • The system must accept only credit card payments, explicitly excluding support for alternative payment types such as debit cards, electronic wallets, or bank transfers.
  • The system should perform real-time authorization of credit card transactions, returning success or error codes along with authorization identifiers.
  • The system must support batching authorized transactions for later settlement, simulating real-world payment batching processes.
  • For batch processing, the system should submit aggregated payment requests to the credit card processor and handle the responses accordingly.
  • The system needs to log all actions and responses for auditing and debugging purposes, ensuring compliance with security and privacy standards.
  • Constraints include maintaining data security, managing transaction integrity, and ensuring system scalability under increased transaction volume.
  • Non-requirements involve support for other payment methods, multi-currency transactions, or integration with external fraud detection systems.

High-Level Design

The system architecture comprises several key components:

  • User Interface (Frontend): Allows customers to input their credit card details and initiate purchases. Communicates with the payment system via HTTP/HTTPS.
  • Storefront Interface: Integrates with the payment system backend to send transaction details for authorization and receive confirmation messages.
  • Payment Processing Service: The core module managing the transaction lifecycle—receiving requests, performing authorization calls, batching transactions, and processing settlements.
  • Authorization Module: Sends real-time authorization requests to the external credit card processor and records responses.
  • Batch Processing Module: Collects authorized transactions, formulates batch requests, and submits them for settlement at scheduled intervals.
  • External Credit Card Processor Interface: Provides API endpoints for authorization and batch payment requests, adhering to the processor’s specifications.
  • Logging and Monitoring: Tracks all transactions and responses, facilitating audit trails and troubleshooting.

Control flow begins with the user submitting payment details through the frontend. The storefront sends this data to the Payment Processing Service, which invokes the Authorization Module to perform real-time authorization via the external API. If authorized, the transaction is stored for batch processing. At scheduled intervals, the Batch Processing Module compiles authorized transactions and submits batch requests through the external API, handling responses to finalize settlements.

Communication Protocols

  • Between customer browser and system: HTTPS for secure data transmission.
  • Within the system: JSON-formatted messages encapsulate transaction data between modules for consistency and ease of parsing.
  • External API interactions with the credit card processor: Proprietary protocols as specified by the processor’s API documentation, typically over HTTPS with OAuth or API keys for authentication.

Resource Planning

The system should be designed to handle an increasing number of transactions through load balancing, database sharding, and scalable cloud infrastructure. For example, cloud services like AWS or Azure can provide elastic compute resources, and NoSQL databases can accommodate high write throughput. Monitoring tools help anticipate load and scale resources proactively, maintaining system responsiveness and uptime.

Deployment Environment

The system will be deployed on a cloud platform such as AWS, leveraging services like EC2, RDS, and Lambda functions. Security features including SSL/TLS, IAM policies, and encrypted data storage are vital. The external credit card API will be integrated via secure endpoints, with safeguarding measures to prevent data breaches and ensure PCI DSS compliance.

Implementation Details

Key implementation aspects include implementing secure storage for transaction data, handling exceptions gracefully, and ensuring the idempotency of API calls to avoid duplications. Design patterns such as singleton for configuration management, factory for creating API clients, and observer for logging can be employed. Comprehensive unit tests and integration tests are necessary to verify component functionality and external interactions.

Conclusion

This high-level design outlines a secure, scalable, and modular payment processing system tailored for online credit card transactions. By combining real-time authorization, batch processing, and detailed logging, the system mimics real-world payment workflows while being adaptable to future expansions such as multi-currency support, multi-payment methods, and advanced fraud detection mechanisms. Implementing this design with proper security practices and robust resource management ensures a reliable foundation for online commerce applications.

References

  • Harrison, Sarah. 2021. Payment Systems: Design and Implementation. New York: Academic Press.
  • Kumar, R. 2019. "Secure Payment Gateway Integration." Journal of Financial Technology 5 (2): 45-58.
  • Jones, A., and T. Lee. 2020. Cloud Infrastructure for Payment Systems. Boston: Tech Publishers.
  • Oracle. 2022. Secure Coding Guidelines for Payment Systems. Retrieved from https://www.oracle.com/security-guidelines
  • Visa. 2022. API Specifications for Payment Processing. Visa Developer Center.
  • PayPal. 2023. Integration Guide for Payment Systems. PayPal Developer.
  • Kim, D. 2018. "Scalability in Payment Processing Architectures." International Journal of Cloud Computing 12 (4): 341-356.
  • Sullivan, M. 2020. Cybersecurity for Payment Applications. London: Security Press.
  • Smith, J., and D. Wilson. 2021. "Design Patterns in Payment Software." Software Engineering Journal 27 (7): 78-89.
  • Gartner. 2022. "Emerging Trends in Digital Payment Security." Gartner Reports, accessed March 10, 2023.

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