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Foto de Ismael Sánchez Aguilera Repullo

Ismael Sánchez Aguilera Repullo

Backend Developer · Java · Spring Boot · Microservices

About

4.5 years writing Java backend. Spring Boot, microservices, keeping legacy systems from blowing up mid-migration. I’ve worked at NTT Data, Ayesa, Minsait, Softtek, Luca-TIC and now Aubay. Always on the stuff I actually care about: integration, stability, and code the next dev can read without cursing me.

Started Computer Engineering at Jaén, jumped off in time, finished with a vocational degree in software development. Picked up videogame design along the way, so my professional stack lives next to LUA scripts for FiveM servers and Discord bots in Python. The weird combo works.

I enjoy chasing weird bugs, refactoring legacy without breaking it, and architectures you can explain over one coffee. Solid English (a 3-month exchange in the Netherlands and the Shell Eco Marathon in Rotterdam helped). Remote-first.

On personal projects I go outside what I already know and use AI to learn faster. This CV is built with Astro, TypeScript and Cloudflare, none of which were part of my daily stack. It’s all on the repo if you want to poke around.

Not actively looking. If the project's interesting, let's talk.

Key achievements

−25 % technical debt leading the Java legacy modernisation at Softtek
99.9 % sustained production uptime over 2 years
−30 % deployment errors after automating CI/CD with Jenkins
Inditex Snowflake ↔ DB2 data reconciliation for enterprise reporting

Experience

  1. Aubay

    — Software Developer

    Seville (remote) (client: Accenture)

    After the previous contract wrapped, same client (Accenture), same domain. Moved from L3 support to shipping new features.

    • Refactored and migrated legacy EJB-based services to REST APIs on Spring Boot. Modernising the stack without breaking anyone still consuming it (anybody who’s touched EJB knows why this hurts).
    • Building new features on the client’s REST platform.
    • SonarQube as the quality gate, Jenkins for deploys.
    • Team of 14, code review on every merge to main.
    • Java
    • Spring Boot
    • REST APIs
    • SQL
    • Jenkins
    • SonarQube

  2. Luca-TIC

    — Application Support Analyst

    Seville (client: Accenture)

    L3 on distributed systems. The bug that had already gone through L1 and L2 without repro-ing landed here.

    • Hunted production bugs buried in the logs of four different microservices. The ones L1 and L2 couldn’t reproduce.
    • Deep code analysis across Java, Spring Boot, Angular and Node.js, catching critical defects early.
    • Redesigned Apache Kafka topics and consumers to decouple services that had been coupled for way too long.
    • Incident investigation with Kibana and Jenkins pipelines. PostgreSQL and MongoDB when the root cause was in the data and not in the code, which happens more often than you’d think.
    • Java
    • Spring Boot
    • Angular
    • Node.js
    • Kafka
    • Kibana
    • Jenkins
    • PostgreSQL
    • MongoDB

  3. Softtek

    — Software Developer

    Seville

    The role where the most stuff happened. Two years. Modernisation, automation, support and reporting for Inditex.

    • Led the legacy codebase migration to Java 8/11/17 with hexagonal architecture, lambdas and Spring Boot. Technical debt down 25 %.
    • Caught bottlenecks using design patterns (Singleton, Factory) and Kafka for real-time messaging. −15 % latency on critical flows.
    • Automated CI/CD pipelines with Jenkins: predictable PRE/PRO deployments and −30 % deploy errors.
    • N1/N2 production support glued to Grafana log analysis. Sustained 99.9 % uptime on key apps.
    • Snowflake ↔ DB2 data reconciliation with proper SQL for Inditex enterprise reporting.
    • RESTful APIs to wire legacy internal systems into the new services.

    "Stands out for his strong willingness to take on new challenges, always eager to learn and contribute. Ismael will be a valuable addition to any company in the sector, and a great teammate who brings good energy to the team."

    — Verónica Arteaga Pérez , HR Representative, Softtek Digital Solutions
    • Java 8/11/17
    • Spring Boot
    • hexagonal architecture
    • Kafka
    • Jenkins
    • Snowflake
    • DB2
    • Docker
    • Grafana

  4. Minsait (Indra)

    — Software Technician

    Seville

    • Full-stack Java and Spring Boot microservices, clean front-back integration.
    • Critical bugs squashed: system errors down 15 % and key feature response times down 20 %.
    • Heavy code review and pre-release testing. Post-release issues close to zero.
    • Java
    • Spring Boot microservices

  5. Ayesa

    — Junior Developer

    Seville

    • Java development with strong focus on code review and optimised SQL queries.
    • −15 % post-release bugs, −20 % project delivery time.
    • Java
    • SQL

  6. NTT DATA Europe & LATAM

    — Junior Developer

    Málaga

    First job. Where I learned that the bug doesn’t show up until the test fires.

    • Set up automated testing protocols. +30 % testing efficiency.
    • Tech troubleshooting that freed the rest of the team to push features.
    • Java
    • automated testing

Projects

Skills

Languages

  • Java █████ 5/5
  • Sql ████░ 4/5
  • Python ███░░ 3/5
  • Javascript ███░░ 3/5
  • Lua ███░░ 3/5
  • Typescript ██░░░ 2/5

Frameworks

  • spring-boot
  • spring-cloud
  • spring-security
  • junit
  • mockito
  • angular
  • ionic
  • node-js
  • discord-py

Infrastructure

  • docker
  • git
  • jenkins
  • kafka
  • kibana
  • grafana
  • linux
  • kubernetes

Databases

  • postgresql
  • mongodb
  • db2
  • snowflake
  • sql-server

Soft skills

Debug y troubleshooting profundo · Comunicación cross-functional · Mentoring de juniors · Documentación técnica clara

Education

Year School Qualification
2015 I.E.S Jándula · Andújar High School Diploma
2015 → 2016 University of Jaén Computer Engineering (changed direction)
2016 → 2019 IES Francisco de los Ríos · Fernán Núñez Higher Technician in Cross-Platform App Development (DAM)
2020 → 2021 IES Ángel de Saavedra · Córdoba Higher Technician in Video Game Design

Bootcamps

  • Everis / NTT Data — Java + Microservicios
  • Everis / NTT Data — .NET
  • Indra — Java + Microservicios

Other

  • Shell Eco Marathon Rotterdam — technician in eco-car competition
  • 3-month academic exchange in the Netherlands
  • 12 years at English language academy
  • Award for building a remote-controlled car with Arduino sensors