João Fernandes Email & Phone Number

At Quaderno I improve our developer experience, and our public API. I also build features and fix bugs related to its integrations with external APIs.Highlights include:- Reduced test build time by 50%.- Diagnosed and resolved memory issues which caused CI builds and deploys to become stuck.- Introduced integration tests with Capybara and Selenium.- Implemented two factor authentication.- Improved performance for public API endpoints by reducing and optimising database operations.- Solved scalability issues in database migrations by introducing a workflow with Percona's pt-online-schema-change.- Introduced continuous delivery via feature flags.- Encrypted customer personal information in the database using the AES-GCM algorithm.Technologies used:Ruby on RailsMySQLRedisElasticSearchStimulusCoffeescriptSidekiqRSpecCapybaraNewRelicSemaphoreCI

Worked as a remote contractor for a fully remote team developing a social network with over 8 million members and 6 billion monthly requests.Highlights include:- Integrated the site's reporting functionality with Help Scout- Expanding the functionality of a user blocking another one to be reflected in all areas of the website, including comments on content of users unrelated to the block, and mentions of the blocked user- Improving the integration between the repository containing the main application and another repository with the community guidelines defined in YAML- Implemented redesigned responsive versions of existing pages, including image and video upload pagesTechnologies used:Ruby on RailsVue.jsMySQLRedisElasticSearchSidekiqGitKubernetesRSpecCapybaraCircleCI

Work remotely on part time projects alongside my full time job:- Built a testimonial page for the Alto Pharmacy landing site, in collaboration with the design agency Saint Friend- Worked on an app to connect Shopify accounting with QuickBooks

Barcelona Area, Spain

Did full stack development on the platform's recruiter tools.Highlights include:- Implemented image and video updates for company profiles- Implemented GDPR compliance on B2B services- Migrated services from Ruby on Rails 4.2 to 5.2- Introduced a test driven culture in the frontend code- Improved error logging with Sentry- Mentored junior developers following their graduation from a coding bootcampTechnologies used:Ruby on RailsMySQLRSpecMinitestJenkinsKubernetesReactJestReact testing libraryGit

Barcelona Area, Spain

Helped migrate an existing double entry accounting system to a more flexible one. This involved writing the new system, porting existing code that depended on the old one, and migrating the existing records with minimal downtime.Technologies used:Ruby on RailsRSpecPostgreSQLAWSGit

Lisbon Area, Portugal / London Area, United Kingdom

Full-stack Ruby on Rails development in an agile environment. Responsible for development, infrastructure and testing of the Seedrs platform.Technologies used:Ruby on RailsSASSCucumberRSpecJavascriptEmber.jsGit

Development of a framework for the development of web interfaces that are ready to be used with the Microsoft Kinect. Technology includes Javascript with JQuery, HTML, CSS and C#.

Porto Area, Portugal

Responsible for helping students with their Algorithm Design and Analysis projects.

Master Of Science (M.Sc.), Computer Software Engineering, 16 Out Of 20

Informatics

Erasmus student for one semester. Had classes of Wireless Systems, Network Algorithms, Multimodal Interaction and Advanced Software.