João Dias Barbosa, Mobile Developer in Porto, Portugal
João Dias Barbosa

Mobile Developer in Porto, Portugal

Member since February 4, 2014
João is a passionate iOS and Android developer with a strong attention to detail that has yielded great apps. He has delivered many projects for millions of users, for both startups and big companies, and he's worked extensively on back-end and API integrations. He has a very positive attitude and works well both alone and on teams.
João is now available for hire




Porto, Portugal



Preferred Environment

Git, Android Studio, Xcode, Android, iOS

The most amazing... I've built was Cashtag, a mobile payments app that allows anyone to pay their friends in seconds directly from their account and for free.


  • iOS Developer

    2019 - 2020
    Patron Technology
    • Built custom integrations for several apps on top of a common codebase.
    • Supported integration with Facebook for an event sharing feature within the festivals.
    • Fixed bugs on a music player.
    • Created a ticket provider that allowed event attendants to check in to certain shows.
    • Worked on several custom design changes across various apps.
    Technologies: Java, HTML, Objective-C, Swift
  • iOS Developer (Contract)

    2017 - 2019
    • Built iOS clienteling apps for multiple high-end fashion brands, to be used by sales assistants within the boutiques.
    • Created an iOS framework that allows the clienteling apps to be built reusing all the front-end code; Features would be developed once for all customers, in a fully native environment.
    • Leveraged Payworks iOS framework in a direct purchase flow which enabled store assistants to be able to handle transactions in the device itself using a card reader and/or AliPay.
    • Built two separate streams of related results for product searches using Cortexica Vision Systems API, iOS CoreGraphics framework, and IBM Visual Search API.
    • Built a standalone iPad app for user signups, intended to enhance the experience for users subscribing to services. Completed with user signature.
    Technologies: Bitrise, CocoaPods, Swift
  • Mobile Software Engineer

    2012 - 2019
    Glazed Solutions
    • Brought many iOS and Android apps from concept to the App Store.
    • Created wireframes as well as redesigned and adapted existing apps to newer OS versions.
    • Designed and worked on RESTful APIs and back ends for mobile apps using Python.
    • Proposed technical and architectural solutions and improvements to existing tech stacks.
    • Used Agile methodologies and software management tools to work with teams across the world.
    Technologies: Python, Django, Java, Objective-C, Android, iOS
  • iOS/Android Developer

    2015 - 2016
    Small Planet
    • Developed for the Wall Art app, in both Android and iOS.
    • Created an authentication feature for the Android app.
    • Fixed bugs and made performance improvements on the display of images into the respective frames of the available layouts for the iOS app.
    • Fixed bugs on filters applied to images for the iOS app.
    • Added animations and other UI changes for both Android and iOS apps.
    • Added Mixpanel SDK and built a manager to handle the creation of events on the app and track the user's actions.
    Technologies: Objective-C, Java
  • iOS Developer

    2015 - 2016
    • Developed the data model and the apps architecture.
    • Built an interface for iBeacon communication.
    • Developed the logic and architecture of the events that should be generated by the interaction (location/proximity) of the user with the iBeacons.
    • Implemented all of the user Interaction/design of the app.
    • Implemented different algorithms to enhance the reliability of the iBeacons signal and its interaction with the apps events/logic.
    Technologies: BlueCats, Swift, iOS
  • iOS Developer

    2015 - 2015
    Keepy (via Toptal)
    • Improved a video and audio in-app player.
    • Enhanced the app's performance by removing critical overall issues.
    • Created a all-new onboarding feature for new users.
    • Implemented design changes.
    Technologies: Objective-C, iOS
  • iOS Developer

    2015 - 2015
    Rocket Internet
    • Worked on the Kaymu iOS app redesign.
    • Built dynamic interface components that were reused throughout the app.
    • Developed a dynamic process to build custom UI forms according to a schema delivered via an API.
    • Created a custom photo cropping tool.
    • Built the entire settings logic.
    Technologies: Objective-C
  • Android Developer, iOS Developer (Contract)

    2014 - 2015
    • Developed an Android and iOS object tracker app that located external devices via Bluetooth.
    • Integrated with Parse Android lib, REST API, and cloud functions.
    • Implemented push notification and geolocation queries.
    • Adapted the app navigation flow and the UX/UI following Google's material design guidelines.
    • Implemented the authentication system, allowing both Facebook and email registration.
    Technologies: Swift, Java
  • iOS Developer, Back-end Developer (Contract)

    2013 - 2014
    • Developed an iOS peer-to-peer payments app.
    • Built the app's design and navigation flows using AutoLayout.
    • Integrated with a bank API to receive and forward payments.
    • Created and documented a RESTful mobile API using Django REST Framework v2.
    • Developed a push notifications service, both on the server and on the iOS side.
    Technologies: Django REST Framework, Python, Objective-C
  • Android Developer, Back-end Developer

    2012 - 2013
    • Developed an Android app where users can create checkpoint-based racing tracks and compete with other users.
    • Built the app's UX/UI and navigation flows.
    • Implemented the authentication system, allowing both Facebook and email registration.
    • Built a non-authenticated flow with some limited functionalities.
    • Built the app with Android 4 UI components, maintaining compatibility with 2.3 versions.
    Technologies: Django REST Framework, Python, Java
  • iOS Developer and Back-end Developer (Contract)

    2012 - 2013
    • Developed an iOS journaling app to store pictures and notes and share them with friends and family.
    • Created and documented a RESTful mobile API in Django.
    • Implemented a permissions system, making each media item available to or editable by specific users or groups of users.
    • Implemented the authentication system, allowing both Facebook and email registration, and the notification system.
    • Created wireframes, and redesigned UX and navigation flows.
    Technologies: Django REST Framework, Python, Objective-C
  • Mobile Engineering Intern

    2012 - 2012
    Glazed Solutions
    • Worked on a big-data tracking app.
    • Refactored an existing native app to a hybrid app that used a WebView to display charts.
    • Created an iOS visualization toolkit.
    • Developed a data visualization recommender that proposed plot types based on the characteristics of multivariable datasets.
    • Built a chart library using some of the most innovative data-visualization frameworks like D3.js.
    Technologies: D3.js, Data Visualization, Objective-C, CSS, JavaScript, HTML5, PhoneGap, iOS
  • Mobile Software Engineer

    2011 - 2011
    To Better Solutions
    • Developed an intelligent task scheduler Android app.
    • Created an algorithm that suggested time management tips to the user based on her tasks.
    • Designed and implemented app UI, following Android design guidelines.
    • Defined and implemented a mobile API, model schema, and data handling guidelines for the project.
    • Worked on requirements analysis, project management, and client communication.
    Technologies: Java, Android


  • Treasured (Development)

    An iOS journaling app to store pictures and notes and share them with friends and family.

  • Cashtag (Development)

    An iOS peer-to-peer payments app. Cashtag was a 2013 Seedcamp winner.

  • EatMyDirt (Development)

    An Android app where users can create checkpoint-based racing tracks and compete with other users.

  • Lapa Android (Development)

    An Android object tracker app that locates external devices via Bluetooth.

  • Statz.Me Visualization Framework (Development)

    A JavaScript-based engine that generates statistical visualization methods fitting the respective data types, built for an iOS app.

  • Lapa iOS (Development)

    An iOS object tracker app that locates external devices via Bluetooth.

  • Kaymu (Development)

    An iOS app for the leading online marketplace in developing countries. I implemented the new design and built flexible custom interface components that could be reused through all the app.

  • Keepy (Development)

    An iOS journaling app to store pictures, videos, and notes of children to be shared with friends and family.

  • Beacinsight (Development)

    A healthcare workflow application for clinicians and administrators. Using iBeacons to track the user's location, its main purpose is to capture the interplay of key resources in the context of patient encounters and also giving clinicians a more upgraded insight into the patient's current state.

  • Wall Art (Development)

    White-label Android/iOS app to create wall decorations by allowing the user to select different frames from a wide range of available layouts that could hold pieces of art or personal photos.

  • Seamless Platform (Development)

    White-label iOS-based platform that held multiple clienteling apps for different fashion brands to be used by sales assistants inside stores.

  • Patron Technology (Development)

    An iOS/Android app that provides a deeper engagement between users and music festivals by integrating features like interactive maps, schedule data and music discovery tools.


  • Languages

    Objective-C, Java, Swift, Python, JavaScript, HTML5, CSS, HTML
  • Frameworks

    iOS SDK, UIkit, Android SDK, PhoneGap, Django REST Framework, Django, Core Data
  • Libraries/APIs

    CocoaPods, Alamofire, Parse SDK, Butterknife, Retrofit, Mixpanel API, Facebook API, Twitter API, Foursquare API, Core Animation, D3.js, Google AdWords, RxSwift
  • Tools

    Xcode, Aptana, Git Flow, GitHub, Interface Builder, Google Analytics, Crashlytics, Android Studio, Eclipse IDE, Instabug, Git, TextMate
  • Paradigms

    Scrum, Agile Software Development, Kanban, Model View Viewmodel (MVVM), Model View Controller (MVC), Mobile Development, VIPER Architecture
  • Platforms

    iOS, Android, Bitrise, Linux
  • Storage

    JSON, MySQL, PostgreSQL
  • Other

    Pull Requests, Mobile App Development, Mobile Apps, Mobile UX, Mobile UI, Data Visualization, BlueCats, Combine


  • Master's degree in Computer Science
    2007 - 2012
    University of Porto - Porto

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