yaperos · DRK2601 · Jan 6, 2026 · Jan 6, 2026 · Jan 6, 2026 · Jan 6, 2026
diff --git a/README.md b/README.md
@@ -1,82 +1,151 @@
-# Yape Code Challenge :rocket:
 
-Our code challenge will let you marvel us with your Jedi coding skills :smile:. 
+## Overview
 
-Don't forget that the proper way to submit your work is to fork the repo and create a PR :wink: ... have fun !!
+This project implements a transaction processing system with asynchronous antifraud validation using an event-driven microservices architecture.
 
-- [Problem](#problem)
-- [Tech Stack](#tech_stack)
-- [Send us your challenge](#send_us_your_challenge)
+Every transaction is:
 
-# Problem
+- Created with an initial pending status
+- Sent to an antifraud service via Kafka
+- Validated asynchronously
+- Updated to approved or rejected
 
-Every time a financial transaction is created it must be validated by our anti-fraud microservice and then the same service sends a message back to update the transaction status.
-For now, we have only three transaction statuses:
+The solution prioritizes decoupling, scalability, and eventual consistency, following real-world financial system patterns.
 
-<ol>
-  <li>pending</li>
-  <li>approved</li>
-  <li>rejected</li>  
-</ol>
 
-Every transaction with a value greater than 1000 should be rejected.
+## Architecture
 
-```mermaid
-  flowchart LR
-    Transaction -- Save Transaction with pending Status --> transactionDatabase[(Database)]
-    Transaction --Send transaction Created event--> Anti-Fraud
-    Anti-Fraud -- Send transaction Status Approved event--> Transaction
-    Anti-Fraud -- Send transaction Status Rejected event--> Transaction
-    Transaction -- Update transaction Status event--> transactionDatabase[(Database)]
+[Grafic](https://drive.google.com/file/d/1OkKfq8jrwy62WnkhHKUrhjgYM3QiBgFL/view?usp=sharing)
+
+
+## Design Decisions
+
+**Why Kafka?**
+
+- Decouples transaction creation from antifraud validation
+- Allows horizontal scaling of antifraud workers
+- Enables eventual consistency
+- Prevents tight coupling between services
+
+**Why separate Antifraud Service?**
+
+- Each microservice owns a single responsibility
+- Antifraud does not access the transaction database
+- Communication happens only through events
+
+**Why asynchronous validation?**
+
+- Transactions are not blocked by antifraud latency
+- System remains responsive under high load
+- Mirrors real banking / fintech flows
+
+
+## Services
+
+■ Transaction Service
+
+- REST API (NestJS)
+
+- PostgreSQL persistence (Prisma)
+
+- Kafka producer & consumer
+
+- Manages transaction lifecycle
+
+■ Antifraud Service
+
+- Kafka consumer & producer only
+
+- No HTTP server
+
+- No database
+
+- Applies antifraud rule:
+
+    » value > 1000 → rejected
+
+    » otherwise → approved
+## API Reference
+
+#### Create Transaction
+
+```http
+  POST /transactions
 ```
 
-# Tech Stack
+| Parameter | Type     | Description                |
+| :-------- | :------- | :------------------------- |
+| `api_keyaccountExternalIdDebit` | `string` | **Required**.|
+| `accountExternalIdCredit` | `string` | **Required**. |
+| `tranferTypeId` | `int` | **Required**. 1 for Yapeo/2 for Pago de Servicios/3 for Recarga de Celular |
+| `value` | `float` | **Required**. |
+
+#### Get Transaction
+
+```http
+  GET /transactions/${transactionExternalId}
+```
+
+| Parameter | Type     | Description                       |
+| :-------- | :------- | :-------------------------------- |
+| `transactionExternalId`      | `string` | **Required**.|
+
+
+
+
+## Running Tests
+**Unit Tests**
 
-<ol>
-  <li>Node. You can use any framework you want (i.e. Nestjs with an ORM like TypeOrm or Prisma) </li>
-  <li>Any database</li>
-  <li>Kafka</li>    
-</ol>
+- Business rules validation
+- Initial transaction status
+- Kafka producer mocked
 
-We do provide a `Dockerfile` to help you get started with a dev environment.
+**E2E Tests**
 
-You must have two resources:
+- POST /transactions
+- GET /transactions/:id
+- Prisma and Kafka mocked
 
-1. Resource to create a transaction that must containt:
+To run tests, run the following command
 
-```json
-{
-  "accountExternalIdDebit": "Guid",
-  "accountExternalIdCredit": "Guid",
-  "tranferTypeId": 1,
-  "value": 120
-}
+```bash
+  npm run test
 ```
 
-2. Resource to retrieve a transaction
-
-```json
-{
-  "transactionExternalId": "Guid",
-  "transactionType": {
-    "name": ""
-  },
-  "transactionStatus": {
-    "name": ""
-  },
-  "value": 120,
-  "createdAt": "Date"
-}
+
+## Deployment
+
+**Requirements**
+
+- Docker
+
+- Docker Compose
+
+Run everything: 
+
+```bash
+  docker compose up --build
 ```
+This starts:
+
+- PostgreSQL
+- Zookeeper
+- Kafka
+- Transaction Service (port 3000)
+- Antifraud Service (worker)
+
+## Environment Variables
+
+To run this project, you will need to add the following environment variables to your .env file
+
+`DATABASE_URL="postgresql://postgres:postgres@postgres:5432/postgres"`
 
-## Optional
 
-You can use any approach to store transaction data but you should consider that we may deal with high volume scenarios where we have a huge amount of writes and reads for the same data at the same time. How would you tackle this requirement?
+## Feedback
 
-You can use Graphql;
+If you have any feedback, please reach out to us at andersson26012000@gmail.com
 
-# Send us your challenge
 
-When you finish your challenge, after forking a repository, you **must** open a pull request to our repository. There are no limitations to the implementation, you can follow the programming paradigm, modularization, and style that you feel is the most appropriate solution.
+## Authors
 
-If you have any questions, please let us know.
+- Piero Andersson Sanchez Bazan (BackEnd Developer)
diff --git a/antifraud-service/.gitignore b/antifraud-service/.gitignore
@@ -0,0 +1,56 @@
+# compiled output
+/dist
+/node_modules
+/build
+
+# Logs
+logs
+*.log
+npm-debug.log*
+pnpm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+
+# OS
+.DS_Store
+
+# Tests
+/coverage
+/.nyc_output
+
+# IDEs and editors
+/.idea
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# IDE - VSCode
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# temp directory
+.temp
+.tmp
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
diff --git a/antifraud-service/.prettierrc b/antifraud-service/.prettierrc
@@ -0,0 +1,4 @@
+{
+  "singleQuote": true,
+  "trailingComma": "all"
+}
diff --git a/antifraud-service/Dockerfile b/antifraud-service/Dockerfile
@@ -0,0 +1,12 @@
+FROM node:20-alpine
+
+WORKDIR /app
+
+COPY package*.json ./
+RUN npm install
+
+COPY . .
+
+RUN npm run build
+
+CMD ["npm", "run", "start:prod"]
diff --git a/antifraud-service/README.md b/antifraud-service/README.md
@@ -0,0 +1,98 @@
+<p align="center">
+  <a href="http://nestjs.com/" target="blank"><img src="https://nestjs.com/img/logo-small.svg" width="120" alt="Nest Logo" /></a>
+</p>
+
+[circleci-image]: https://img.shields.io/circleci/build/github/nestjs/nest/master?token=abc123def456
+[circleci-url]: https://circleci.com/gh/nestjs/nest
+
+  <p align="center">A progressive <a href="http://nodejs.org" target="_blank">Node.js</a> framework for building efficient and scalable server-side applications.</p>
+    <p align="center">
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/v/@nestjs/core.svg" alt="NPM Version" /></a>
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/l/@nestjs/core.svg" alt="Package License" /></a>
+<a href="https://www.npmjs.com/~nestjscore" target="_blank"><img src="https://img.shields.io/npm/dm/@nestjs/common.svg" alt="NPM Downloads" /></a>
+<a href="https://circleci.com/gh/nestjs/nest" target="_blank"><img src="https://img.shields.io/circleci/build/github/nestjs/nest/master" alt="CircleCI" /></a>
+<a href="https://discord.gg/G7Qnnhy" target="_blank"><img src="https://img.shields.io/badge/discord-online-brightgreen.svg" alt="Discord"/></a>
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+  <a href="https://twitter.com/nestframework" target="_blank"><img src="https://img.shields.io/twitter/follow/nestframework.svg?style=social&label=Follow" alt="Follow us on Twitter"></a>
+</p>
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+
+## Description
+
+[Nest](https://github.com/nestjs/nest) framework TypeScript starter repository.
+
+## Project setup
+
+```bash
+$ npm install
+```
+
+## Compile and run the project
+
+```bash
+# development
+$ npm run start
+
+# watch mode
+$ npm run start:dev
+
+# production mode
+$ npm run start:prod
+```
+
+## Run tests
+
+```bash
+# unit tests
+$ npm run test
+
+# e2e tests
+$ npm run test:e2e
+
+# test coverage
+$ npm run test:cov
+```
+
+## Deployment
+
+When you're ready to deploy your NestJS application to production, there are some key steps you can take to ensure it runs as efficiently as possible. Check out the [deployment documentation](https://docs.nestjs.com/deployment) for more information.
+
+If you are looking for a cloud-based platform to deploy your NestJS application, check out [Mau](https://mau.nestjs.com), our official platform for deploying NestJS applications on AWS. Mau makes deployment straightforward and fast, requiring just a few simple steps:
+
+```bash
+$ npm install -g @nestjs/mau
+$ mau deploy
+```
+
+With Mau, you can deploy your application in just a few clicks, allowing you to focus on building features rather than managing infrastructure.
+
+## Resources
+
+Check out a few resources that may come in handy when working with NestJS:
+
+- Visit the [NestJS Documentation](https://docs.nestjs.com) to learn more about the framework.
+- For questions and support, please visit our [Discord channel](https://discord.gg/G7Qnnhy).
+- To dive deeper and get more hands-on experience, check out our official video [courses](https://courses.nestjs.com/).
+- Deploy your application to AWS with the help of [NestJS Mau](https://mau.nestjs.com) in just a few clicks.
+- Visualize your application graph and interact with the NestJS application in real-time using [NestJS Devtools](https://devtools.nestjs.com).
+- Need help with your project (part-time to full-time)? Check out our official [enterprise support](https://enterprise.nestjs.com).
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+- Looking for a job, or have a job to offer? Check out our official [Jobs board](https://jobs.nestjs.com).
+
+## Support
+
+Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support by the amazing backers. If you'd like to join them, please [read more here](https://docs.nestjs.com/support).
+
+## Stay in touch
+
+- Author - [Kamil Myśliwiec](https://twitter.com/kammysliwiec)
+- Website - [https://nestjs.com](https://nestjs.com/)
+- Twitter - [@nestframework](https://twitter.com/nestframework)
+
+## License
+
+Nest is [MIT licensed](https://github.com/nestjs/nest/blob/master/LICENSE).