Guillermo Calvo

Currently working with the Unity Foundation.

My team is responsible for the development of both Open Source frameworks, Micronaut and Grails. I contributed with several bugfixes and new features.

Apart from these JVM-based frameworks, I’m also working on some other internal projects that will be open sourced eventually.

As part of OCI’s Groovy, Grails, and Micronaut Team, I worked on several client projects. One of the most relevant ones was an innovative banking-as-a-service platform.

Our team developed a highly-scalable, robust payments system based on a distributed architecture for a leading fintech company. This event-driven platform implemented many third-party integration points, such as Jack Henry and Feedzai.

Microservices were powered by Micronaut, deployed on Google Cloud, and communicating using Apache Kafka.

Working at YouCanBook.me, in Engineering Team. I focused on the development and maintenance of the backend systems that powered the scheduling app.

My team was responsible for:

• Monitoring and maintenance of YouCanBook.me APIs, services and processes.
• Creating scalable, robust web services and new features that are deployed on a daily basis.
• Refactoring existing legacy systems, generating a clean, maintainable and testable code.
• Improving the in-house billing and subscriptions component.

Working at Rakuten, in RAPID Team, EC Platform Department. I was one of the main developers of an internal, open-source project which provided a set of Java libraries and other tools to other teams, empowering them to focus on the business logic.

Our team leaded a company-wide initiative, whose mission was to accelerate micro-services development through standardization and factorization. We were in charge of building the next generation platform of the company, using state-of-the-art technologies and adopting new concepts and paradigms.

My team was responsible for:

• Introducing new technologies and frameworks to the company.
• Providing trainings and best practices to other teams.
• Designing and providing architectural and technical support on the next generation e-commerce platform system.
• Implementing distributed backend API systems that support high traffic demand and provide a 24x7 reliable service.
• Developing the continuous refactors and re-architecture of the system, to comply with the increasing scalability demand and requirements.

Working at Rakuten, in Checkout Team of Rakuten Ichiba, Japan’s biggest shopping mall. Our team was in charge of one of the most critical parts of the e-commerce. Checkout is the process a customer must go through when checking out the items in the cart.

My responsibilities included:

• Development, system design and implementation of web applications
• Operations, release managment, system maintenance
• Investigation of any issues in production servers

Working at GFT, on the Technology & Innovation Professional Services Unit. My team was responsible for:

• Identification and adoption of technology trends that may benefit the company
• Standardization and best practices
• Development of frameworks to improve efficiency, scalability, robustness and reusability
• Transfer of technological knowledge to company projects

During the course of my roles, I took part in some projects for a specific German global banking and financial services company.

Working at Hewlett-Packard, providing services for some of the largest banking corporations in Spain.

Most of the projects on which I took part, aimed for the integration of CRM systems (based on Siebel) and several other external information systems. This was achieved by developing a layer of middleware based on web services.

During 2013 I trained as a 3D application developer. I learned Unity3D, an engine with which virtual reality environments can be created for multiple platforms, computers and smartphones.

Kana Memory, an educational app to learn Japanese, is the first Android game I published as an independent game studio.