Projects

A selection of projects I've developed or led in recent years, focusing on Java/Kotlin backend, scalable APIs, and complex integrations.

GateKeeper API

Featured

The GateKeeper API is a RESTful API responsible for managing user registration requests with an administrative approval workflow. Users submit registration requests, which are stored in a temporary table in MySQL. Administrators review, approve, or reject the requests. When approved, the data is migrated to the official user table.

Java 21Spring Boot 4.0.2Spring Security (JWT)Spring Data JPASpring Web MVCBean ValidationMySQLLombokGradle Kotlin DSL
GitHub2026

ContractFlow API

Featured

Java Spring Boot system for dynamically generating PDF contracts from data sent via API.

Java 21Spring Boot 3Spring SecuritySpring Data JPAJPA/HibernateJWT (JJWT + Auth0)OpenPDFMySQLLombokGradle Kotlin DSL
GitHub2026

Library API

Complete RESTful API for managing a library (books, authors and loans) developed with Spring Boot and Java. Allows registration and control of Books (Title, Author, Description, Year), Authors (Name, Nationality), Users (username, email, password, role), Loans and Returns.

Java 17Spring Boot 3Spring Data JPAHibernateH2 / MySQLSpringDoc OpenAPI (Swagger)Gradle
GitHub2025

Orion Payments

Payment processing system using Spring Boot, with webhooks, event queues, and a complete status flow. Project focused on clean architecture, external integration, and asynchronous communication for a backend portfolio. Features full CRUD for payments, multiple statuses (PENDING, SUCCESS, ERROR), Kafka integration for async notifications, DTOs, Spring Data JPA, and Swagger UI for API docs.

Java 17Spring Boot 3.xSpring Data JPAKafkaLombokH2 / MySQLSwaggerGradle
GitHub2025

Smart Task Scheduler

Intelligent task scheduler in pure Java using ScheduledExecutorService. Loads tasks from JSON, executes based on absolute timestamps (ISO-8601), validates expiration, and prioritizes. Focuses on native concurrency, clean architecture, and no heavy external dependencies (no Quartz or Spring).

Java (pure)java.util.concurrentScheduledExecutorServiceGson (custom TypeAdapter)Java Time API (Instant)Maven
GitHub2026

Ultimate Item Actions

A Minecraft plugin that introduces custom items for players, where each item has interactive behavior that triggers specific actions in-game.

Java 17SpigotBukkitLombokAnnotationsGradle Kotlin DSL
GitHub2026