challenge yape - solution

[paulccuno]

📝 Description

This PR implements a based on microservices solution using NestJS, Kafka, Docker, GraphQL, and Prisma to manage transactions in a secure and scalable way.

📌 Objective

Develop a distributed system to process transactions efficiently and with anti-fraud validations.

🛠 Solution Architecture

Three microservices were implemented:

1. Client-Gateway (GraphQL API):

   • Acts as the entry point for clients.
   • Exposes GraphQL endpoints to interact with the microservices.
   • Publishes events to Kafka.

2. ExternalTransaction (Transaction Management):

   • Responsible for receiving transactions from Kafka and storing them in PostgreSQL with Prisma.
   • Exposes its own events for other microservices to consume.

3. AntiFraud (Transaction Validation):

   • Listens to Kafka events to analyze suspicious transactions.
   • Returns a validation response approving or rejecting the transactions.

🔍 How to Test

1️⃣ Clone the Repository

git clone https://github.com/yaperos/app-nodejs-codechallenge.git
cd app-nodejs-codechallenge

2️⃣ Start Services with Docker

docker-compose up --build

This will start Kafka, PostgreSQL, and the three microservices.

Note: Environment variables are already set.

3️⃣ Access GraphQL Playground

Once the services are running, you can access http://localhost:3000/graphql to test the Client-Gateway endpoints.

4️⃣ Test with GraphQL

Example mutation to initiate a transaction:

mutation CreateTransaction {
  createTransaction(
    createTransactionInput: {
      accountExternalIdCredit: "a0608cb6-27b2-4fd7-a203-f941e95fad6d"
      accountExternalIdDebit: "ab6836c5-63c7-4160-a023-b6078d0d9b23"
      tranferTypeId: 13
      value: 1500
    }
  ) {
    id
    externalDebitAccount {
      id
    }
    externalCreditAccount {
      id
    }
    type {
      id
      name
    }
    status {
      id
      name
    }
    transferType {
      id
      name
    }
    value
    createdAt
    updatedAt
  }
}