Octavio Calleya García - Software Engineer portfolio

Octavio Calleya García

Software Engineer, Java & Kotlin Backend Developer

Software Craftmanship.

Delivering robust and scalable backend systems with integrity and expertise.

Projects

Showcasing impactful projects and technical achievements.

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Musicott

Java 8 desktop music manager application using JavaFX and CSS, with REST client, dependency injection, and comprehensive testing.

Desktop
Backend
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music-commons

A modular, reactive Kotlin library for managing audio libraries, playlists, and waveform visualizations.

Library
Backend
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transgressoft-commons

A reactive programming library in Kotlin using Publisher-Subscriber pattern, Coroutines, and Domain Driven Design.

Library
Backend

Experience

Professional journey and career timeline.

Software Engineer, Java Backend Engineer

Cisco SystemsPrague (remote)
2024 - 2025

Design, implementation, testing, and maintenance of new features, bugfixes and architectural changes of a JVM backend (Java 8, Java 17 and Scala) using Spring Boot and React + Redux frontend.

JavaScala+3 more
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Software Engineer, Java Backend Engineer

S&P GlobalPrague (remote)
2023 - 2024

Implementation, testing and maintenance of features in a Java backend system with a Swing based desktop application.

JavaJavaFX+3 more
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Software Engineer, Java Backend Engineer

flatexDegiroPrague (remote)
2022 - 2023

Implementation of features in microservices codebase written in Java, using Spring and Spring Boot using REST APIs.

JavaSpring Boot+2 more
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Skills

Key skills that define my professional identity.

Java

Core language with 9+ years of professional experience across enterprise systems, microservices, and desktop applications.

Kotlin

Modern JVM language used for building reactive libraries, coroutine-based frameworks, and Spring Boot services.

Spring Framework

Deep expertise in Spring Boot, Spring MVC, and Spring ecosystem for enterprise backend development.

Concurrent Programming

Extensive experience with multithreading, reactive programming, coroutines, and high-throughput systems.

API Design

Design and implementation of RESTful APIs, OpenAPI specifications, and GraphQL schemas.

JavaFX

Desktop application development with rich UI components and media capabilities.