timilehinpromise / mintyn

Backend Engineer Assessment

Mintyn Card Verification Service

Overview

This application provides a card verification service using a variety of design principles and patterns for clean and efficient software development. It includes features like card scheme verification and statistics gathering.

Key Features

• Card Scheme Verification: Determine the details of a card, such as its validity, scheme (VISA, MasterCard, etc.), and issuing bank.
• Statistics Gathering: Track and display the number of verifications made for each card.

Technologies

• Spring Boot: For creating the web application.
• WebClient: For reactive web requests.
• Caffeine: For efficient in-memory caching.
• PostgreSQL: As the database system.
• Docker: For containerizing and managing the application environment.
• JUnit 5: For unit testing the application.
• Mockito: For mocking objects in tests.

Running the Application

Prerequisites

• Docker
• Docker Compose

Design Principles and Patterns in Our Application

1. Strategy Pattern

   What It Does: Allows us to choose between different algorithms or processes.

   Our Use Case: We use different strategies (like BinListProvider) for processing card information, easily switchable based on our needs.

2. Factory Pattern

   What It Does: Helps in creating objects without specifying the exact class to be created.

   Our Use Case: CardProcessorFactory determines which card processor to use, simplifying object creation in our system.

3. Dependency Injection

   What It Does: Manages how objects obtain their dependencies.

   Our Use Case: We use Spring to inject dependencies like WebClient, ensuring flexibility and easing testing.

4. Template Method Pattern

   What It Does: Outlines an algorithm's structure but lets subclasses modify specific steps.

   Our Use Case: If our AbstractCardProcessor defines a general card processing workflow, allowing subclasses to tailor specific parts.

5. Reactive Programming

   What It Is: A programming style based on data flows and change propagation.

   Our Use Case: We utilize reactive types like Mono for building responsive and non-blocking components.

6. Single Responsibility Principle

   What It Implies: Each class should have one purpose, one reason to change.

   Our Use Case: Classes like BinListProvider and CardServiceImpl are focused on a single functionality, making our code more coherent and easier to maintain.

7. Open/Closed Principle

   What It Advocates: Code entities should be open for extension but closed for modification.

   Our Use Case: Our use of interfaces and abstraction allows for adding new features without altering existing, stable code.

Steps to Run

Clone the Repository:

git clone https://github.com/TimilehinPromise/mintyn.git

Navigate to Project Directory:

cd mintyn

Start the Application: Use Docker Compose to start the application along with the PostgreSQL database.

docker-compose up

The service will be available on http://localhost:9060.

Accessing the Application:

https://documenter.getpostman.com/view/15243512/2s9YsJAryf

Use the postman collection

Stopping the Application

To stop the application, run the following command:

docker-compose down