![Joao da Silva Fernandes, Developer in Porto, Portugal](https://assets.toptal.io/images?url=https%3A%2F%2Fbs-uploads.toptal.io%2Fblackfish-uploads%2Ftalent%2F332881%2Fpicture%2Foptimized%2Fhuge-fe2d53006e47e543c6fcc871c057db6f.jpg&width=524)
Joao da Silva Fernandes
Verified Expert in Engineering
Full-stack Developer
João is a full-stack developer focused on Ruby on Rails who delves into the front end and infrastructure. He started his career mainly working in startup environments until 2017 when he joined Xing, Germany's most active professional network platform. He has been working as a remote contractor since 2020. João strives for long-term maintainability through code quality and a proper delivery process where testing, code reviews, and commit history are prioritized.
Portfolio
Experience
Availability
Preferred Environment
React, Ruby on Rails (RoR), Ruby, Visual Studio Code (VS Code), Git
The most amazing...
...feeling of value I've had was introducing a testing culture to a group of front-end developers and seeing the confidence in our code increase.
Work Experience
Ruby on Rails Developer for API Integrations
Topkey, Inc.
- Implemented integration with Unit to onboard customers and issue and manage debit cards, and receive transaction information.
- Handled the implementation of integration with Codat to allow users to set up their accounting and export transactions.
- Set up CI with GitHub Actions for testing and linting multiple repositories.
- Built the staging and production environments with Cloud66 and Digital Ocean.
Senior Software Engineer (Contractor)
Quaderno
- Reduced the test build time by 50% by optimizing database cleaning and usage of Elasticsearch.
- Diagnosed and resolved memory issues that caused CI builds and deploys to become stuck.
- Introduced integration tests with Capybara and Selenium.
- Implemented 2-factor authentication for the platform administrators, and for the clients.
- Improved performance for public API endpoints by reducing and optimizing database operations.
- Automated the setup for users connecting their Quaderno account with Xero.
- Enabled the team to run migrations on its tables with dozens of millions of records.
Senior Software Engineer (Contractor)
FetLife
- Integrated the website's content and user reporting functionality with Help Scout.
- Expanded the functionality of a user blocking another one to be reflected in all areas of the website, including comments on the content of users unrelated to the block, and mentions of the blocked user.
- Improved the integration between the repository containing the main application and another repository with the community guidelines defined in YAML to make user and content reporting more configurable by the moderation team.
- Implemented redesigned responsive versions of the existing pages, including image and video upload pages.
Senior Software Engineer
- Ensured GDPR compliance by stopping the storage of unnecessary personal data and implementing personal data downloading and deletion.
- Migrated some services from Ruby on Rails 4 to Ruby on Rails 5.
- Added image and video updates for company profiles.
- Integrated company profiles into the company's iOS app via WebView.
- Improved the user experience of recruiter tools by allowing them to perform bulk actions on candidates.
- Introduced a test-driven culture to the company's front-end ecosystem using Jest and React Testing Library.
Senior Software Engineer
Novicap
- Migrated the accounting system to a new double-entry system.
- Improved the GitFlow and code-review culture in the company.
Consultant
MovingWorlds
- Maintained the platform at a point where no developers had been working on it for months.
- Optimized back-end admin panels to accommodate the platform activity.
- Fixed critical bugs that were disrupting the operations team and the users.
- Hired and onboarded a long-term maintainer for the platform.
Software Engineer
Seedrs
- Worked on financial reconciliation mechanisms with credit card payments and currency transfers.
- Implemented a site-wide responsive redesign with a gradual page per page release.
- Built the legal compliance mechanisms according to the UK's FCA requirements.
- Contributed to the development of a platform for the operations team to review crowdfunding pitches sentence by sentence.
- Created a dashboard for entrepreneurs to manage their crowdfunding campaigns.
Experience
Testimonials Page for Alto Pharmacy
https://alto.com/reviewsTechnologies: Jekyll, Sass, HTML, JavaScript, jQuery
Framework to Navigate Web Pages Using the Microsoft Kinect
Site-wide Responsive Redesign
http://www.seedrs.com/investTechnologies: Haml, Sass, jQuery
Rails 5 Upgrade
https://www.xing.com/companiesHead of the Program for Portugal's National Conference of IT Students (ENEI 2013)
Talk | Mob Programming to Deliver Better Software
https://github.com/PixelsCamp/talks/blob/master/2019/mob-programming_joao-fernandes.mdSkills
Languages
Ruby, SQL, JavaScript, HTML, TypeScript, CSS, Sass, Haml
Frameworks
Ruby on Rails (RoR), minitest, Redux, Stimulus, Selenium, Ember.js, Cypress, Capybara, Jest
Tools
Git, GitHub, RSpec, Sentry, Cucumber, GitLab, Bitbucket, Jenkins, Graylog, Cloud66
Paradigms
Testing, Continuous Deployment, Continuous Delivery (CD), Agile, Scrum, Kanban, Object-oriented Programming (OOP), Pair Programming, Mob Programming, Continuous Integration (CI), REST, Functional Programming
Other
Full-stack, Back-end, API Integration, APIs, Front-end, Domain-driven Design (DDD), Analytics, Responsive UI, SEO Tools, Codat, Unit
Libraries/APIs
React, Vue, Sidekiq, API Development, Stripe, jQuery, Node.js, Marionette.js
Platforms
New Relic, Visual Studio Code (VS Code), Amazon Web Services (AWS), Docker, Kubernetes, Heroku, Mixpanel, Unix, DigitalOcean
Storage
PostgreSQL, MySQL, Redis, MongoDB
Education
Master's Degree in Software Engineering
University of Porto, Faculty of Engineering - Porto, Portugal
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