Marina Mas Perez, Developer in Porto, Portugal
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Marina Mas Perez

Verified Expert  in Engineering

React Developer

Location
Porto, Portugal
Toptal Member Since
August 19, 2022

Marina is a professional software engineer with over four years of recent experience specializing in React and React Native. She has a bachelor's degree in mathematics and a four-year background in business intelligence analysis, where she has honed her analytical and collaboration skills. Marina is curious, loves new challenges, and constantly seeks innovative solutions to everyday problems.

JavaScriptReactReact ReduxJestUnit TestingCSSPostgreSQLAndroidiOSExpo.ioReact Native for WebGraphQLCalculusStatisticsData VisualizationDiscrete MathematicsExpoStyled-components

Portfolio

T-Mobile
React Native, Jest, Cucumber, Unit Testing, APIs, Firebase, Storybook...
BOHO Ventures LLC
React Native, GraphQL, Expo, Mobile App Development, GraphQL Code Generator...
Webflow
JavaScript, React, Cypress, Reselect, Jest, Flow, Styled-components, CircleCI...

Experience

JavaScript - 6 yearsReact - 5 yearsJest - 4 yearsReact Native - 4 yearsReact Redux - 4 yearsReact Navigation - 4 yearsUnit Testing - 4 yearsStyled-components - 3 years

Availability

Part-time

Preferred Environment

React Native, JavaScript, React

The most amazing...

...app I've developed is a React Native mobile app that I built as the only developer on the team, which is now published in the Play Store and App Store.

Work Experience

Senior React Native Developer

2022 - PRESENT
T-Mobile
  • Reduced the app's starting time by 20%, creating a better user experience and reducing the number of comments on performance.
  • Designed new T-Mobile sim flows for in-app handling.
  • Upgraded the app's core packages successfully with React Native and React Navigation.
  • Increased the app's ratings in both the Play Store and App Store.
Technologies: React Native, Jest, Cucumber, Unit Testing, APIs, Firebase, Storybook, React Native for Web, GraphQL, Android, iOS, Mobile

Front-end React Native Developer

2022 - 2023
BOHO Ventures LLC
  • Successfully designed and implemented the front end architecture for the BOHO, a wine and spirits app, ensuring a seamless user experience, using my experience with Expo and GraphQL.
  • Developed and integrated various app features, such as user registration, login, and profile management, enhancing the app's functionality.
  • Successfully collaborated with the design team to translate UI/UX designs into fully functional and visually appealing app screens.
  • Implemented QR code scanning functionality, enabling users to access relevant information and make donations easily.
  • Optimized the app's performance and loading times, ensuring a smooth and efficient user experience.
  • Successfully conducted rigorous testing and debugging to identify and resolve any issues, ensuring the app's stability and reliability.
  • Actively participated in team discussions, providing valuable insights and contributing to the project's overall progress and success.
  • Demonstrated adaptability and problem-solving skills, overcoming challenges and meeting deadlines throughout the development process.
Technologies: React Native, GraphQL, Expo, Mobile App Development, GraphQL Code Generator, App Store, Google Play Store

React Developer

2021 - 2021
Webflow
  • Rewrote the React components to the custom implementation using an internal workflow description language, focusing on reducing complexity while keeping all the current functionalities.
  • Migrated all the atoms set as the project's target before the project was finished, allowing us to write better testing for each migration.
  • Fixed bugs found on production in less than two hours.
Technologies: JavaScript, React, Cypress, Reselect, Jest, Flow, Styled-components, CircleCI, Redux

React Native Developer

2020 - 2021
Mandala Ground Labs
  • Built a mobile application, as the only developer on the team, using React Native and successfully published it in the Play Store and App Store.
  • Used i18next for internationalization, resulting in the app's availability in more than ten languages.
  • Created an AI that can play against the user within the app, with the possibility of selecting the AI's level.
Technologies: JavaScript, React Native, React, React Redux, Reselect, Expo, TypeScript, App Store, Google Play Store, Fastlane, Styled-components, Android, iOS, Mobile

React Native Developer

2019 - 2020
British Gas
  • Migrated native apps to React Native for the British Gas product Hive, used daily by over 1.5 million customers, and achieved a 4.5+ rating in the Play Store and App Store.
  • Built new user flows for several app areas, such as heating and lights. The app is focused on smart home solutions for heating, lights, cameras, and sensors, which the user can install and control remotely.
  • Contributed proactively to the overall improvement of the app's accessibility features.
Technologies: JavaScript, React Native, React Redux, Sagas, Flow, Jest, Reselect, Styled-components, CircleCI, Storybook, Android, iOS, Mobile

Senior BI Analyst

2018 - 2020
William Hill
  • Collaborated with analytics leadership to define guidelines and policies for using Tableau and defined and implemented corresponding processes and controls.
  • Administered user accesses to Tableau workbook applications and capabilities as requested and approved.
  • Interfaced with different teams to gather requirements for new projects on Tableau and worked on them.
  • Achieved changing the workflow of some departments, such as AML, to use Tableau and improve work efficiency.
Technologies: Tableau, Tableau Server, Microsoft SQL Server, R, JavaScript, Jira, Data Visualization

Business Intelligence Analyst

2017 - 2018
eDreams ODIGEO
  • Analyzed, documented, and implemented reports targeting the different departments.
  • Prepared optimized data sources using data mining and data processing.
  • Maintained and improved existing reports addressed to each of the business areas.
Technologies: MySQL, QlikView, Jira

Business Intelligence Analyst

2016 - 2017
CornerJob
  • Automated all the daily reporting and evaluation of main KPIs.
  • Designed and implemented machine learning algorithms to improve the experience in B2B and B2C.
  • Built a recommendation system based on user preferences and location.
  • Extracted data and developed specific reports to improve the application's performance.
Technologies: RStudio Shiny, R, JavaScript, PostgreSQL, Python, Tableau, Redshift

Development of a Menu App

A React Native mobile app where a user can select items from a menu and add them to their cart. Each menu item has variants, which the user can choose when adding to the cart. The user can also view and remove items from their cart. This app is a small personal project built to showcase my coding style and technical skills.

Development of a Song Search App

https://github.com/marina713/SongSearchApp
A mobile app built using React Native where the user can browse their favorite music and play a preview of it. It consists of a home screen for searching and sorting music and a player screen for playing music. This app is a small personal project built to showcase my coding style and technical skills.

T-Mobile Netherlands

https://apps.apple.com/es/app/ik-ben/id385103386
I took over the development of the Ben app, one of the Dutch T-mobile sub-brands. The app is a React Native app written in TypeScript.

I then launched an MVP of the React Native app for the web, replacing the self-service part of the website and sharing most of the app code-base. Meanwhile, I developed new features, maintained the iOS and Android apps, and supported forming a new team and migrating services.

BOHO - Buy One Help Others

https://apps.apple.com/us/app/boho-buy-one-help-others/id6444543461?uo=2
A React Native project built with Expo. I took charge of every aspect, from conception to implementation and publishing in the stores, showcasing my expertise in mobile development.
Throughout the entire development process, I demonstrated strong problem-solving skills, attention to detail, and a commitment to delivering a high-quality app.
2010 - 2015

Bachelor's Degree in Mathematics

University of Barcelona - Barcelona, Spain

Languages

JavaScript, CSS, HTML, C, Java, R, TypeScript, Python, GraphQL

Frameworks

React Native, Jest, Cypress, Redux, RStudio Shiny, Detox

Libraries/APIs

React, React Redux, React Navigation, React Native for Web, Reselect, Redux-Saga

Paradigms

Unit Testing, App Development, Mobile App Design, Azure DevOps

Platforms

Mobile, Android, iOS, Firebase, QlikView

Other

Styled-components, App Submission, Sagas, Storybook, Design, Arithmetic, Critical Thinking, Topology, R Programming, Algebra, Calculus, Statistics, Tableau Server, Data Visualization, App Store, Google Play Store, APIs, Discrete Mathematics, Mobile App Development, GraphQL Code Generator

Tools

Expo.io, MATLAB, Tableau, Jira, Flow, CircleCI, Expo, Fastlane, Cucumber, Sentry, Webpack

Storage

PostgreSQL, Microsoft SQL Server, MySQL, Redshift

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