I am a proactive, organized, and adaptable developer with 6 years of experience leading the development of scalable tech solutions. I focus on full-cycle software development and continual system enhancement, delivering high-impact solutions that reduce costs, improve efficiency, and optimize development workflows. Being self-taught and constantly learning, I have strong adaptability for any type of project and stack. I enjoy working on diverse projects, from transport management and hospital systems to gaming and e-commerce platforms. I have experience working internationally and thrive in collaborative environments where I can contribute to efficient, secure, and innovative software products.

Jose Luis Calleja Garcia

I am a proactive, organized, and adaptable developer with 6 years of experience leading the development of scalable tech solutions. I focus on full-cycle software development and continual system enhancement, delivering high-impact solutions that reduce costs, improve efficiency, and optimize development workflows. Being self-taught and constantly learning, I have strong adaptability for any type of project and stack. I enjoy working on diverse projects, from transport management and hospital systems to gaming and e-commerce platforms. I have experience working internationally and thrive in collaborative environments where I can contribute to efficient, secure, and innovative software products.

Available to hire

I am a proactive, organized, and adaptable developer with 6 years of experience leading the development of scalable tech solutions. I focus on full-cycle software development and continual system enhancement, delivering high-impact solutions that reduce costs, improve efficiency, and optimize development workflows. Being self-taught and constantly learning, I have strong adaptability for any type of project and stack.

I enjoy working on diverse projects, from transport management and hospital systems to gaming and e-commerce platforms. I have experience working internationally and thrive in collaborative environments where I can contribute to efficient, secure, and innovative software products.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
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Language

English
Advanced
Spanish; Castilian
Fluent

Work Experience

Java Engineer at Indra
September 30, 2024 - July 11, 2025
Designed and implemented radar ticketing/payment systems for public transport authorities (including Redsys and European consortium). Developed robust full-stack applications for transport management used in Europe and US, significantly improving real-time data tracking and image recognition technology, reducing operational response time. Optimized Oracle procedures for faster client reporting and improved user satisfaction. Engaged in international client meetings to align technical requirements, reducing miscommunication and increasing trust. Technologies used: Java 7–11, Spring, Linux, Hibernate, SOAP, JQuery, Angular, React, Oracle, Microservices, SQL Server, JBOSS, PostgreSQL, ANT, Tomcat, REST APIs, GitHub, JavaScript.
C# Developer – Freelancer at Freelancer
January 31, 2024 - July 11, 2025
Designed modular gameplay systems such as AI, combat, inventory, physics, abilities, and resources management. Developed scalable and reusable systems optimized for performance. Enabled rapid prototyping and smooth gameplay experience in real-time 3D environments. Technologies used included C#, Unity, Visual Studio, GitHub, Jira, and IOP.
Full-Stack Engineer at Dedalus
September 30, 2023 - July 11, 2025
Developed critical modules for hospital management systems and disease-tracking hardware integration across multiple countries. Reverse-engineered legacy systems and resolved urgent client issues under tight deadlines, improving system uptime and client retention. Helped hospitals digitize key medical processes and maintained 24/7 functionality in systems used by healthcare professionals across Europe. Technologies included Java 8, Spring, XML, Vue.js, JavaScript, JQuery, Oracle DB, ANT, Microservices, JBoss, MVC, Docker, Jenkins, IntelliJ.
C# Developer at Freelancer
September 1, 2023 - January 31, 2024
Designed modular gameplay systems such as AI, combat, inventory, physics, abilities, and resource management. Developed scalable and reusable systems optimized for performance, enabling rapid prototyping and smooth gameplay experience in real-time 3D environments.
C# Developer at Freelancer
September 1, 2023 - January 31, 2024
Designed modular gameplay systems including AI, combat, inventory, physics, abilities, and resources management. Developed scalable and reusable systems optimized for performance. Impact: Enabled rapid prototyping and smooth gameplay experience in real-time 3D environments.
Java Engineer at Indra
March 1, 2023 - September 30, 2024
Designed and implemented radar ticketing/payment systems for public transport authorities in Europe and the US. Developed robust full-stack applications improving real-time data tracking and image recognition, optimized Oracle procedures for faster client reporting, and engaged in international client meetings to align technical requirements. Boosted system performance and enhanced development efficiency by 30%, contributing to follow-up contract wins.
Java Engineer at Indra
March 1, 2023 - September 30, 2024
Designed and implemented radar ticketing/payment systems for public transport authorities. Developed robust full-stack applications for transport management used in Europe and the US, improving real-time data tracking and image recognition technology. Optimized Oracle procedures to enhance reporting speed. Engaged in international client meetings to align technical requirements. Impact: Boosted system performance and reliability, enhanced development efficiency by 30%, and contributed to winning follow-up contracts.
Full-Stack Engineer at Dedalus
October 1, 2022 - September 30, 2023
Developed modules for hospital management systems and disease-tracking hardware integration across multiple countries. Reverse-engineered legacy systems and resolved client issues under tight deadlines. Helped hospitals digitize key medical processes and maintained 24/7 uptime in systems used by healthcare professionals in Europe.
Full-Stack Engineer at Dedalus
October 1, 2022 - September 30, 2023
Developed critical modules for hospital management systems and disease-tracking hardware integration across multiple countries. Reverse-engineered legacy systems and resolved urgent client issues under tight deadlines, improving system uptime and client retention. Impact: Helped hospitals digitize key medical processes and maintained 24/7 functionality in healthcare systems across Europe.
Full-Stack at Moversfax
September 30, 2022 - July 11, 2025
Rebuilt legacy systems, migrated core backend infrastructure, and documented the entire platform, enhancing security, maintainability, and long-term scalability for future developers. Technology stack included Java 8, Spring Boot, JSP, Vue.js, PHP, Oracle, JavaScript.
Full-Stack at Moversfax
June 1, 2022 - September 30, 2022
Rebuilt legacy systems, migrated core backend infrastructure, and documented the platform, enhancing security, maintainability, and long-term scalability for future developers.
Full-Stack at Moversfax
June 1, 2022 - September 30, 2022
Rebuilt legacy systems, migrated core backend infrastructure, and documented the entire platform. Impact: Enhanced security, maintainability, and long-term scalability for future developers.
Java Dev Analyst at Everis
September 30, 2021 - July 11, 2025
Designed and implemented automated tariff systems and reporting APIs for the Spanish national electricity grid. Participated in technical planning with government entities, ensuring accurate implementation of energy regulations. Resulted in improved energy pricing transparency and reduced manual processing errors, lowering support tickets by 40%. Technologies used: Java 7, J2EE, Angular, Docker, Oracle, JSP, SOAP.
Full-Stack – Freelancer at Freelancer
September 30, 2021 - July 11, 2025
Developed and designed a secure, SEO-optimized flight school site with custom SMTP-based contact system and e-commerce features for products and classes. Created a secure environment for online payment transactions, optimizing full-stack e-commerce site with secure transactions and custom contact system, achieving high Google SEO rankings and smooth visual attractiveness. Technologies used: PHP (CodeIgniter), HTML5, Bootstrap, JavaScript, JQuery, API, MVC.
Full-Stack at Freelancer
June 1, 2021 - September 30, 2021
Developed and designed a secure, SEO-optimized flight school site with custom SMTP-based contact system and e-commerce features, optimizing for secure transactions and achieving high Google SEO rankings and smooth visual design.
Full-Stack at Freelancer ULM
June 1, 2021 - September 30, 2021
Developed and designed a secure, SEO-optimized flight school website. Designed and implemented a custom SMTP-based contact system. Added e-commerce features for products and classes with secure online payment transactions. Impact: Achieved high Google SEO rankings and smooth, visually attractive site.
Java Dev Analyst at Everis
January 1, 2021 - September 30, 2021
Designed and implemented automated tariff systems and reporting APIs for the Spanish national electricity grid. Participated in technical planning with government entities to ensure accurate energy regulation implementation. Improved energy pricing transparency and reduced manual processing errors, lowering support tickets by 40%.
Java Dev Analyst at Everis
January 1, 2021 - September 30, 2021
Designed and implemented automated tariff systems and reporting APIs for the Spanish national electricity grid. Participated in technical planning with government entities to ensure compliance with energy regulations. Impact: Improved energy pricing transparency and reduced manual processing errors, lowering support tickets by 40%.
Full-Stack at CUCC University
December 31, 2020 - July 11, 2025
Built a cloud-based academic platform streamlining course management, internal communication, and documentation for professors and students. Designed full-stack solutions for online education, implemented secure remote work environments. Implemented secure Azure deployment, automated student registration, and integrated academic systems across Latin America, North America, and Europe. Led and developed a custom application for university fairs. Increased productivity by 65%, student acquisition by 25%, reduced administrative overhead, and improved academic engagement. Technologies used include PHP (CodeIgniter), JQuery, Git, GitHub, HTML5, CSS (Bootstrap), JavaScript, MySQL, Vagrant, Azure, PowerShell, Apache2, JSON, PhpStorm, Scrum Agile.
Java Developer at El Corte Inglés
September 30, 2019 - July 11, 2025
Created a drag-and-drop internal app builder for non-developers to create custom pages and workflows. Handled large-scale data visualization, processed web stats, and developed internal bug-tracking tools. Accelerated content creation and facilitated non-technical departments with digital tools. Technologies used: Symfony, Websites, Java 7, JSP, JSON, XML, Jenkins, HTML5, J2EE.
Full-Stack at CUCC University
September 1, 2019 - December 31, 2020
Built cloud-based academic platforms to streamline course management and internal communications, designed full-stack solutions for online education, implemented secure remote work environments, automated student registration, and integrated academic systems spanning Latin America, North America, and Europe. Led development of a custom application for university fairs, increasing productivity and student acquisition significantly.
Full-Stack at CUCC University
September 1, 2019 - December 31, 2020
Built a cloud-based academic platform streamlining course management, communication, and documentation. Designed secure online education solutions and remote work environments. Implemented Azure deployment, automated student registration, and integrated international academic systems. Led development of a custom application for university fairs. Impact: Increased productivity by 65% and student acquisition by 25%, reduced administrative overhead, and improved academic engagement.
Java Developer at El Corte Inglés
June 1, 2018 - September 30, 2019
Created a drag-and-drop internal app builder enabling non-developers to create custom pages and workflows. Developed large-scale data visualization tools and internal bug-tracking systems, accelerating content creation and digital tool adoption across departments.
Java Developer at El Corte Inglés
June 1, 2018 - September 30, 2019
Created a drag-and-drop internal app builder allowing non-developers to create custom pages and workflows. Handled large-scale data visualization and developed internal bug-tracking tools. Impact: Accelerated content creation and enabled non-technical departments with digital tools.

Education

Diploma at Tamwood International College
September 1, 2021 - August 31, 2022
Diploma at Arcipreste de Hita
September 1, 2019 - June 30, 2021
Diploma at Brianda de Mendoza
September 1, 2018 - June 30, 2020
Diploma at Brianda de Mendoza
September 1, 2014 - June 30, 2018
Diploma at Tamwood International College
September 1, 2021 - August 31, 2022
Diploma at Arcipreste de Hita
September 1, 2019 - June 30, 2021
Diploma at Brianda de Mendoza
September 1, 2018 - June 30, 2020
Diploma at Brianda de Mendoza
September 1, 2014 - June 30, 2018
Bachelor's at Open University
January 1, 2024 - January 1, 2024
Diploma at Tamwood International College
September 1, 2021 - August 31, 2022
Diploma at Arcipreste de Hita
September 1, 2019 - June 30, 2021
Diploma at Brianda de Mendoza
September 1, 2018 - June 30, 2020
Diploma at Brianda de Mendoza
September 1, 2012 - June 30, 2014

Qualifications

C# Development in Unity Engine
January 1, 2023 - December 31, 2023
Video Games Development in Unreal Engine
January 1, 2020 - December 31, 2020
Project Management with Agile Methodologies
January 1, 2019 - December 31, 2019
JQuery Development
January 1, 2018 - December 31, 2018
Web Expert in Ethical Hacking
January 1, 2018 - December 31, 2018
C# Development in Unity Engine
January 1, 2023 - December 31, 2023
Video Games Development in Unreal Engine
January 1, 2020 - December 31, 2020
Project Management with Agile Methodologies
January 1, 2019 - December 31, 2019
JQuery Development
January 1, 2018 - December 31, 2018
Web Expert in Ethical Hacking
January 1, 2018 - December 31, 2018
C# Development in Unity Engine
January 1, 2023 - December 31, 2023
Video Games Development in Unreal Engine
January 1, 2020 - December 31, 2020
Project Management with Agile Methodologies
January 1, 2019 - December 31, 2019
JQuery Development
January 1, 2018 - December 31, 2018
Web Expert in Ethical Hacking
January 1, 2018 - December 31, 2018

Industry Experience

Software & Internet, Gaming, Transportation & Logistics, Healthcare, Education, Energy & Utilities, Retail, Government