Hotmart Code Challenge

Context:

This document outlines my attempt to solve a coding challenge for Hotmart. Below is the full description of the challenge provided as part of the task. For the challenge, I used SpringBoot.

Version

1.2.1

Context

Imagine you're a developer at a tech company, and your new task is to build part of a high-traffic product marketplace.

So far, you’ve received the description of the following entities:

• Product: ID, name, description, creation date
• Buyer: ID, name
• Seller: ID, name
• Product Category: ID, name
• Sale: ID, seller, buyer, product

When a buyer purchases a product, they can rate it from 0 to 5 (this rating is not yet mapped in the entities).

One of the most important parts of the marketplace being built is the product search feature. Each product will receive a daily ranking score calculated using the following formula:

X = Average rating of the product over the last 12 months  
Y = Number of sales / days the product has existed  
Z = Number of news articles related to the product category on the current day

Score = X + Y + Z

The Challenge

Your task is to:

• Create a CRUD (Create, Read, Update, Delete) for products.

• Build a Product API exposing the CRUD operations (list, find, delete, update, insert).

• Create a service to search for products ordered by ranking, filtered by name and category.

  • The service output must include the fields currentDate and searchTerm, along with the list of products matching the search. Each returned product must include: { id, name, description, creationDate, score }

• All services must be auditable.

Notes:

• To get the number of news articles for a given category, you can use the API at https://newsapi.org/. Model the entities accordingly to fit the scenario. Also, create initial data for these entities.
• You should query the https://newsapi.org/docs/endpoints/top-headlines endpoint 4 times a day (feel free to choose the best strategy), store the data locally, and use the publication date of each article to support the required logic.

What We Expect from Your Test

• We want to assess your technical skills, analytical thinking (preferably through short and clear commit messages), and how you present results.
• You don’t have to implement everything listed, but we want a clear sense of how you approach problem-solving.
• Feel free to include/modify/remove entities, attributes, technologies, jobs, or anything else necessary to better address the challenge.

Specifically, in your project delivery, we would like to see:

• Documentation
• Appropriate use of libraries
• Code written with clear semantics – readability is just as important as performance, and they don’t have to conflict.
• Decoupling and a clear hierarchy between system components
• Automated testing

Things That Would Impress Us

• Fault tolerance – make the service more robust when calling the external news API.
• Caching – research and implement a cache library to speed up searches.
• Support for pagination in product listings
• Project containerization – Docker
• Strategy to avoid over-consuming the news API
• Tests beyond unit tests (e.g., integration, end-to-end)
• Use of a versioning tool for data loading scripts
• Well-structured solution architecture, appropriate design patterns, and object-oriented design
• Securing endpoints that persist data (you may use in-memory user/password auth)
• All code written in English

What We Don’t Want to See

• Evidence that you didn’t do the test yourself
• Missing the main objectives of the challenge
• Very unreadable code
• Lack of documentation or instructions on how to run your project

Evaluation Criteria

• Completion of proposed objectives
• Code semantics, structure, readability, maintainability, scalability, and decision-making
• Project organization
• Solution architecture, appropriate use of design patterns and OOP
• Performance, resilience, and error handling
• API documentation
• Entity modeling

Requirements

• Must use Java or Kotlin
• Do not use tools or databases with commercial licenses
• Each table must contain at least 100 records