Helder Martins Email & Phone Number

Amsterdam, North Holland, Netherlands

Amsterdam Area, Netherlands

Stockholm, Sweden

As a Master degree project, I researched how does deep recurrent neural networks used as a churn predictor model compares to the state-of-the-art methods for this task when applied to Spotify's user base. The project also involved performing a detailed data exploration of the user behavior on the platform as to create a dataset with representative features that could maximize the predictor's accuracy for estimating the disposition of the user towards the service, and exploring how different aspects of the user data impacts the ability of the models to learn and predict.

Stockholm, Sweden

Researched virtualization tools for better deployment of Ericsson's internal applications using Docker and Jenkins. Researched and implanted an online Java IDE to be used by Ericsson's developer teams.

Porto Alegre Area, Brazil

Responsible for creating and maintaining several backend systems that can properly withstand the high volume of requests received daily in Terra website, like:* Creating high performance web servers that dynamically assemble personalized web pages for each user of the website, using Python's Tornado framework in conjunction with NginX as a load balancer and MongoDB as the database backend.* Creating RESTful APIs to gather user information in the website (like preferences, pages visited), while providing an interface between this data and other applications of the site.* Prototyping a news recommender system using Apache Mahout's algorithms for collaborative filtering, using the pages visited by the user as the base of our recommendation. * Fully recreating the development process of our frontend teams using Continuous Integration techniques, like continuous deployment using Jenkins, Git and GitHub Enterprise, automated Javascript tests using Node.js and Grunt, code validation using JSLint, dev preview servers that allow testing new features before production, A/B test systems that allow evaluation of code changes.* Improving the reliability of a feeds importer system responsible for importing almost all content of the website into our databases, using Apache's QPid and C++-* Improving security of the website's authentication system by blocking brute force attacks, using C and Memcached.

Design and development of Android apps.

Porto Alegre Area, Brazil

Responsible for updating firmware and software for Hewlett-Packard next generation blade servers, called Superdome 2.

Porto Alegre Area, Brazil

Worked on several projects, mainly for Terra Networks. Some of them involved :- Web services for on-line payment in C;- A DNS server file system organizer, for better use of BIND 9, also in C;- A high performance and availability program for generic tasks management in Java;- A robust report generator for all Terra's suppliers in C.

Porto Alegre Area, Brazil

'C / C + +' programmer in the automation business. Maintenance and optimization of Point of Sale Terminal (POST) software for supermarkets and retail stores. Maintenance of SQL database.

PHP and HTML programmer for Núcleo de Tecnologia Digital Aplicada à Educação (NUTED). Participated on ROODA and ETC projects.

Master Of Science (M.Sc.), Machine Learning

Bs, Computer Science