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Alex MartinezAM

Alex Martinez

Full Stack Developer | Web, Apps & Software

€280/day
Madrid, ES
8-15 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Alex

Does your website or app have errors, run slowly, or do you need to build something new from scratch? I'll help you make your digital project work well and look professional, without technical complications.

I work with businesses and individuals who need a website, an app, or a video game that truly works: fast, stable, and without surprises. If you already have a project underway and something is wrong, I'll review and fix it. If you're starting from scratch, I'll accompany you from the first line of code until the product is ready for your users.

I don't just write code; I understand the business behind it. I have real-world experience working in professional environments, resolving production incidents, and optimizing critical processes where failure costs real money. This means that when I work on your project, I prioritize stable functionality, not just making it 'look good' on day one.

✅ Development of web pages
✅ Custom mobile apps
✅ Video games and playable prototypes
✅ Maintenance and bug fixing for existing projects
✅ Integrations: forms, payments, WhatsApp, Analytics
✅ Performance and speed optimization

Clear communication from the first message, realistic deadlines, and no disappearing mid-project.

I'll give you a no-obligation quote before starting, so you know exactly what you're investing in.

Tell me what you need, and let's talk.
  • Spanish

    Native or bilingual

  • English

    Conversational

  • French

    Basic

Can work on-site
Madrid (up to 50km)

Experience

  • NTT Data
    Java Programmer
    March 2025 - Today (1 year and 4 months)
    Madrid, Spain
    • Design, development, and maintenance of applications aiming to optimize their performance.
    • Execution of code reviews to improve software quality. Mentoring junior developers, promoting learning and continuous improvement.
    • Performing unit tests to identify and resolve technical issues.
    JavaScript Java MySQL MongoDB React.js
  • Redsys
    Batch Development
    May 2022 - December 2024 (2 years and 7 months)
    Madrid, Spain
    . Responsible for the development and maintenance of critical batch processes for payment management, primarily using Java, SQL, and MongoDB. . Implemented effective solutions for identifying and correcting errors in the application, ensuring optimal functionality and operational continuity.
    • Optimized the performance of batch processes, achieving a significant reduction in processing times and an improvement in overall system efficiency.
  • Ghenova
    Software Development
    June 2020 - May 2022 (1 year and 11 months)
    Madrid, Spain
    . Participated in the development and maintenance of a naval employee and material management application, collaborating closely within a multidisciplinary team.
    • Served as a point of contact between the technical team and clients, gathering functional requirements and incident reports to ensure the implementation of effective solutions. . Contributed to both the front-end and back-end development of the application, using technologies such as Java, Javascript, SQL, and MongoDB.
    • Performed software installation and configuration in client environments, ensuring successful deployment and a smooth user experience.

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Education

  • Course in Artificial Intelligence and Data Science
    UNIR
    2025
    Curso en Inteligencia Artifical y Data Science
  • Development of Multiplatform Applications, DAM
    Camara Oficial de Comercio de Madrid
    2020
    Desarrollo de aplicaciones Multiplataforma, DAM

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