Diego Castro

The Workshop is a product company specialized in gaming, betting, and fintech platforms. The platform serves more than 500,000 daily active users and processes nearly 1,000 operations per second. The backend is multi-brand and multi-tenant, offering shared services for multiple business lines from a single technical ecosystem.

Key Contributions

• Backend service optimization: Improved performance and system stability of the campaign service by refining exclusion logic and centralizing the task queue, preventing pod overload and achieving a more homogeneous workload distribution.
• Kubernetes cluster upgrade: Participated in the upgrade of the corporate cluster to a new version, deploying all product services into a new production environment. Coordinated with DevOps, Network, and Third Parties teams (both integrated with us and integrated by us) in a complex multi-team process.
• Support task automation: Developed an internal tool to automate processes related to on-call duties: phone redirection, wiki and messaging channel updates, automatic incident logging and ticket generation, including automatic rotation of the support schedule.
• Cross-team collaboration: Participated in code-cleanup initiatives to remove client-specific dependencies and improve service maintainability, as well as developing tools to analyze code impact across multiple teams.
• Creation of a new production environment: Involved in building a new production environment in an additional datacenter, deploying all services from scratch and managing the transition with controlled downtime.
• Innovation and impact: Contributed to a hackathon project focused on optimizing software licenses, achieving 3rd place company-wide.
• Storage optimization: Designed and executed a database cleanup process in the marketing system, significantly reducing required storage.
• Technology migration: Participated in migrating the marketing system from Cassandra to Elasticsearch, improving query efficiency and maintainability.
• Operational reliability: Documented complex technical investigations and standardized critical configurations to facilitate stable and reproducible deployments.

Key Achievements

• Improved campaign execution time by 90–95% through logic optimization and flow refactoring.
• Reduced manual effort in on-call operations through full automation of planning and incident management.
• Supported external teams until full autonomy, improving code quality and delivery efficiency.
• Key contributor in the corporate Kubernetes upgrade program, resolving dependency and configuration blockers across teams and Third Parties.
• Reduced marketing system storage consumption by 15% through data cleanup and optimization processes.
• Contributed to a hackathon project with an estimated savings of €300,000/year in software licensing costs.

Java (17+), Spring Boot, Spring Cloud, REST APIs, Kafka, RabbitMQ, Cassandra, Elasticsearch, Prometheus, Micrometer, PromQL, AlertManager, Grafana, Docker, Kubernetes, Helm, Git, CI/CD (Bamboo), JUnit, Pitest, Mockito, Angular, Jasmine, Selenium, Contract Testing, Scrum/Kanban

Remote (from Madrid, Spain)

I was part of the architecture department of BBVA’s CIB area, working on the “NOVA Platform”, an internal cloud-like environment to host and operate CIB services.

The platform offered: service management through a web interface, REST API definition in OpenAPI, client/server code generation with CLI, Git integration, automatic deployment with Docker, testing and deployment across different environments (dev, pre-production, production), security control, and monitoring.

Key Contributions

• Integrated Python support into a platform originally built for Java.
• Integrated the platform with the bank’s Kubernetes cluster for service deployment, replacing virtual machines.

My role was software engineer and functional analyst, participating in all phases: analysis of specifications, architecture design, and programming.

Main Responsibilities

• Analysis and development of technical specifications
• Backend and frontend programming

Java 8, PostgreSQL, Microservices, REST, Spring Boot, Docker, Swarm, GlusterFS, Python, NodeJS, Git, Maven, Scrum

Madrid, Spain

At Locken, a product company with a small and constantly evolving IT department, I played a versatile role covering analysis, design, development, testing and innovation.

I actively contributed to the product’s technical definition, infrastructure modernization, and adoption of new technologies within the team.

Main Responsibilities

• Development and review of technical and functional specifications
• Architecture design and definition of development standards
• Backend programming (Java, Spring Boot) and web development
• Code review and technical support to the team
• R&D activities and evaluation of new technologies

Featured Projects

• Testing infrastructure refactoring: migration of legacy code to a modular Spring Boot project with continuous integration in Jenkins and Docker, reducing execution time by 60% and cutting duplicated code by more than half.
  • Java 8, Spring Boot, JUnit, Selenium, Jenkins, Docker, Rancher
• Microservices architecture design: backend development for the company’s mobile and web applications using Spring Cloud, Consul, and Docker.
  • Java 8, Spring Boot, Spring Cloud, Consul, Docker, Rancher
• Identity Server deployment: configuration and rollout of WSO2 Identity Server as the authentication core for the entire microservices infrastructure.
  • WSO2 Identity Server, Docker, Rancher
• Corporate chatbot development: creation of a chatbot for Skype and SMS based on Microsoft Bot Framework and Dialogflow, providing a new user support channel.
  • Microsoft Bot Framework, Node.js, Restify, AI, NLP, DialogFlow, Azure Bot Service, Twilio, SMS, REST API, Spring Boot, Spring MVC, Spring State Machine, Redis, Docker, Docker Compose
• BI platform deployment: setup and maintenance of a Pentaho platform for automated report generation.
  • Pentaho, PostgreSQL
• Access management web app: development of a Spring Boot backend with WebSockets and REST API for real-time monitoring of facility access logs.
  • Spring Boot, Apache Camel, XML/RPC, REST API

I also promoted the adoption of emerging technologies such as Docker and Progressive Web Apps, encouraging their use in new department developments.

Madrid, Spain

Backend development of the “Portal Équilibre” project, a microservices-based platform for processing readings from tens of millions of smart electricity meters in French households, with hourly data updates.

My role was software engineer and functional analyst, contributing to all phases: technical analysis, implementation, and testing.

Main Responsibilities

• Development of technical specifications
• Review of functional specifications
• Backend programming in a microservices environment

Java 8, Spring Boot, Spark, Cassandra, Apache Camel, Activiti, JUnit, DB2, REST, Git, Maven, Scrum

Nantes, France

Participation in the launch of the “Programme FIBRE” project, a new web application for Banque de France.

My role was technical lead, with a strong focus on supervising and mentoring a team of mostly junior developers.

Main Responsibilities

• Code review and assurance of technical quality
• Estimation and tracking of technical budgets
• Mentoring and guidance for junior team members
• Review of technical and functional specifications

Java 8, REST, AngularJS 1.5, Angular Material, Angular UI Router, Gulp, Bower, Karma, Jasmine, Protractor, Arquillian, JUnit, Git, Maven

Lille, France

End-to-end development of a web application for managing cogeneration facilities.

My role was technical lead, driving technical design and implementation, while coordinating a small development team.

Main Responsibilities

• Design of common components and establishment of development patterns
• Definition of code structure and project best practices
• Backend and frontend development
• Team coordination and mentoring of junior members

Java 7, JQuery, Thymeleaf, Spring MVC, Spring Security, LDAP, Weblogic, Hibernate, SQL, Oracle, Web Services, JUnit, SVN, Maven, Jenkins

Madrid, Spain

Maintenance and evolution of a web application for managing photovoltaic installation contracts for EDF.

My role was technical lead, contributing to analysis, programming, and coordination of junior team members.

Main Responsibilities

• Technical analysis of functional requirements
• Preparation of technical estimates
• Mentoring and guidance for junior developers
• Backend and frontend programming

Java 6, JQuery, JSP, Struts, Spring, Spring Batch, Weblogic, Hibernate, SQL, Oracle, REST, Web Services, JUnit, DBUnit, SVN, Maven, Jenkins

Madrid, Spain

Development of a web application for searching mass participation races, managing registrations, and ticketing.

Work carried out in an early-stage startup, participating in all phases: architecture design, fullstack development, and infrastructure preparation.

Main Responsibilities

• Application architecture design
• Frontend and backend programming
• Infrastructure setup and management

Java 6, Spring MVC, REST, PayPal integration, Spring Social, Spring Security, Spring Batch, Apache Camel, JSP, HTML, JQuery, AngularJS, Elasticsearch, Spring Data, JPA, Hibernate, MySQL, JUnit, Tomcat, Git

Madrid, Spain

Development of a web application for managing industrial facilities (elevators, refrigeration systems, etc.) and inspection processes.

My role was software engineer and functional analyst, leading a small team and participating in both analysis and programming tasks.

Main Responsibilities

• Management of a small development team
• Technical analysis of functional requirements
• Backend and frontend programming

J2EE, Struts, JSP, JSTL, Servlet, JavaScript, CSS, EJB, Web Services, JUnit, SVN, Weblogic, SQL, Oracle, Maven, Hudson

Bilbao, Spain

Development of a web application for the gaming and entertainment directorate, including license management, facility inspections, and fine collection.

My role was developer, focused on implementation and maintenance of the application.

Main Responsibilities

• Backend and frontend development

J2EE, Struts, Documentum, JSP, JSTL, Servlet, JavaScript, CSS, EJB, MDB, Web Services, JUnit, DBUnit, SVN, Weblogic, SQL, Oracle, Maven, Hudson

Bilbao, Spain

• Data Analysis:
  • Introduction to Classification, Regression, Clustering, Dimension Reduction
• Machine learning:
  • SVM, Decision Tree, Random Forest, K-means, Logistic Regression with SciKit Learn and Spark MLlib
• Deep Learning:
  • Neural Networks, Convolutional Neural Networks, Recurrent Neural Networks with Keras and Tensorflow
• Data preparation with Python:
  • Pandas, Numpy
• Data preparation with R:
  • dplyr, tidyverse
• Advanced Machine learning:
  • Recommendation systems, NLP, Topic Modeling, Approximation algorithm, Sentiment Analysis
• Data visualization:
  • Tableau, ggplot2, Bokeh, d3.js, CartoDB
• Final Master’s Work
  • Automatic Pothole Detection System from Road Surface Images [ES]