Juan Antonio León

About

I'm a Java software engineer and I've spent over 7 years working on critical projects in banking, energy and logistics.

I started studying Telecommunications Engineering. I didn't finish the degree, but those years gave me the foundations to understand how systems work and taught me not to be afraid of complex problems.

Over time I moved from hands-on technical roles to managing and planning teams. I enjoy analysing and re-engineering processes, and writing clean code that is easy to maintain.

I'm self-taught and passionate about technology. I like learning and sharing what I learn with my team.

Experience

1. Senior Java Software Engineer

   Bahia Software · Feb 2024 – present · Remote

   • High-availability backend with Java and Spring for a national banking institution.
   • Technical leadership in analysing and re-engineering banking processes.
   • Test plans to ensure quality in critical environments.
   • Daily AI use: Claude and Gemini as coding support, agents to generate code and tests, and skills that make the team's work easier.

2. Senior Java Software Engineer

   Isotrol · Oct 2022 – Dec 2023 · Spain

   • Energy trading application built on microservices.
   • Query optimisation and handling large volumes of data.
   • Designing robust, scalable architectures.

3. Senior Java Developer

   atSistemas · Apr 2022 – Oct 2022 · Paris, France

   • ERP for international logistics.
   • Middleware integrations and complex reports with JasperReports.

4. Java Developer

   Ayesa · Jun 2019 – Mar 2022 · Hybrid

   • CRM module for the Endesa-Enel project.
   • System integration with Salesforce API and TIBCO.
   • Management and planning of a technical team.

5. Founding partner

   DisMas · Oct 2014 – Aug 2019 · Remote

   • Coaching and training in web design.
   • Blog layout and graphic design.

6. Junior .NET Developer

   everis · Mar 2019 – Jun 2019 · Seville

   • Internship on a .NET project.

7. University secretary

   Colegio Mayor Almonte · Feb 2016 – Sep 2017 · Seville

   • Treasury management for the university club.
   • Organising activities.

Education

• Higher Vocational Training · Web/Multimedia Management and Webmaster

  Centro Educativo Altair · 2017 – 2019

• Telecommunications Engineering

  Studies not completed · Several years

• ESL Language Instructor

  Dublin City University · Exchange · 2018

Stack & skills

Personal projects

• Travel expense sharing app

  Split the costs of trips with friends without the hassle of settling up afterwards.

• MVP image generator for sports clubs

  Creates match-day MVP images for sports associations, ready to post on social media.

Contact

Let's talk. Leave me a message and I'll get back to you as soon as I can. You can also reach me on LinkedIn.