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

Verified Expert  in Engineering

Mobile Developer

Location
Porto, Portugal
Toptal Member Since
April 4, 2014

João is a passionate iOS and Android developer. With strong attention to detail, he has created many great apps and has delivered many projects for millions of users, both startups and big companies. João has worked extensively on back-end and API integrations. A positive attitude allows him to create on his own and in teams.

Portfolio

Gratitude Services Inc
SwiftUI, Swift, iOS, Combine, Shopify, Shopify API
Fruitful
Swift, SwiftUI, XCTest, MessageKit, Auth0, Mobile Apps, Mobile UX, Combine...
Xing
Swift, Objective-C, SwiftUI, GraphQL, Calabash, XCTest, Mobile Apps, Mobile UX...

Experience

Availability

Full-time

Preferred Environment

Git, Android Studio, Xcode, Android, iOS

The most amazing...

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

Work Experience

SwiftUI iOS Developer

2022 - 2022
Gratitude Services Inc
  • Developed a POC that leveraged the usage of iOS App Clips to provide a better experience for a product order flow for a reorder products application.
  • Built a purchase flow composed of a product detail screen and an expandable checkout view using SwiftUI. The product detail screen was fully customizable according to the various product variants available. The product data was available via Shopify API.
  • Built an interaction that, by changing the various product options, would update the current gallery image being displayed to match the resultant product variant.
  • Built an Instagram-stories-like integration that would display promotional videos for a particular product.
Technologies: SwiftUI, Swift, iOS, Combine, Shopify, Shopify API

Senior iOS Developer

2022 - 2022
Fruitful
  • Worked on chat features for a financial guidance app through an integration with the Salesforce Chat SDK and MessageKit.
  • Refactored the app’s high-level architecture and navigation.
  • Built integration with Auth0 to handle authentication.
  • Fixed several bugs related to Salesforce chat events and the chat’s working hours and availability.
Technologies: Swift, SwiftUI, XCTest, MessageKit, Auth0, Mobile Apps, Mobile UX, Combine, Optimizely, Contentful, Salesforce, Refactoring

Senior iOS Developer

2021 - 2022
Xing
  • Built from scratch a new module that held a set of fenced features that would enhance the user’s job search by defining an accurate set of criteria.
  • Followed the MVVM-C pattern and data handling via GraphQL to complete the development.
  • Implemented extensive unit testing (XCTest), UI testing, and end-to-end testing (Calabash).
Technologies: Swift, Objective-C, SwiftUI, GraphQL, Calabash, XCTest, Mobile Apps, Mobile UX, Combine, Refactoring

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 during 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, Mobile Apps, Mobile UX

iOS Developer (Contract)

2017 - 2019
LVMH
  • Built iOS clienteling apps for multiple high-end fashion brands to be used by sales assistants within their 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 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, Cortexica, iOS, Mobile Apps, Mobile UX, XCTest, Refactoring

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, REST APIs, Agile, Mobile Apps, Mobile UX, SQL

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 improved performance on the image display from 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 users' actions.
Technologies: Objective-C, Java, iOS, Android, User Interface (UI), Animation, SDKs, iOS SDK, Mobile Apps, Mobile UX

iOS Developer

2015 - 2016
Beacinsight
  • Developed the data model and the architecture of the app.
  • 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: Swift, iOS, Mobile Apps, Mobile UX

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, Mobile Apps, Mobile UX, Refactoring

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, iOS, User Interface (UI), Mobile Apps, Mobile UX, Refactoring

Android Developer, iOS Developer (Contract)

2014 - 2015
Lapa-App
  • 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, Android, iOS, REST APIs, Bluetooth, User Experience (UX), User Interface (UI), Mobile Apps, Mobile UX

iOS Developer, Back-end Developer (Contract)

2013 - 2014
Cashtag
  • Developed an iOS peer-to-peer payments app.
  • Built the app's design and navigation flows using Auto Layout.
  • 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, iOS, REST APIs, Django, Mobile Apps, Mobile UX

Android Developer, Back-end Developer

2012 - 2013
EatMyDirt
  • 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, Android, User Experience (UX), User Interface (UI), Mobile Apps, Mobile UX

iOS Developer and Back-end Developer (Contract)

2012 - 2013
Treasured
  • 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 notification and authentication system, allowing both Facebook and email registration.
  • Created wireframes, and redesigned UX and navigation flows.
Technologies: Django REST Framework, Python, Objective-C, iOS, REST APIs, Django, User Experience (UX), Mobile Apps, Mobile UX

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, iOS, Refactoring

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 his or 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, User Interface (UI), Communication

XING (New Work)

https://www.xing.com/
An employment-oriented social network targeted at the central Europe market.

Throughout this engagement, I built a new module that held a set of fenced features that would enhance the user's job search by defining an accurate set of criteria. The development was done using UIkit and SwiftUI, following the MVVM-C pattern, handling data via GraphQL. It was supported by extensive unit testing (XCTest), UI testing, and end-to-end testing (Calabash).

Seamless Platform

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

Patron Technology

https://www.greencopper.com/
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.

Cashtag

An iOS peer-to-peer payments app. Cashtag was a 2013 Seedcamp winner.
On this engagement, I have built the iOS app and its back end using the Django Rest framework. I was also responsible for implementing push notifications.

Fruitful

A financial guidance app that provided chat-based and telephone consulting sessions with financial experts.

In this engagement, I worked on chat features through an integration with the Salesforce Chat SDK and MessageKit. I refactored the app’s high-level architecture and navigation and built its integration with Auth0 to handle authentication. Finally, I fixed several bugs related to Salesforce chat events and the chat’s working hours and availability.

Wall Art

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.

Pleasy Play

An interactive game for couples to enhance their intimate relationship through a variety of challenges. I have built the iOS app from the ground up using SwiftUI and Combine following the MVVM pattern.

Lapa iOS

An iOS object tracker app that locates external devices via Bluetooth.
Integrated with Parse Android lib, REST API, and cloud functions. It used a push notification service and geolocation queries. I was responsible for building the iOS app from the ground up and integrating it with the Parse SDK to connect with cloud functions.

Lapa Android

An Android object tracker app that locates external devices via Bluetooth.
Integrated with Parse Android lib, REST API, and cloud functions. It used a push notification service and geolocation queries. I was responsible to build the Android app from the ground up and integrate with Parse SDK to connect with cloud functions.

Treasured

An iOS journaling app to store pictures and notes and share them with friends and family. Throughout this engagement, I was responsible for building the iOS app and the back-end code built using Django Rest framework.

Keepy

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

EatMyDirt

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

Statz.Me Visualization Framework

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

Kaymu

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 apps according to a schema delivered via an API.

Beacinsight

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.
2007 - 2012

Master's Degree in Computer Science

University of Porto - Porto, Portugal

OCTOBER 2022 - PRESENT

The Complete React Native + Hooks Course

Udemy

Libraries/APIs

CocoaPods, Alamofire, Parse SDK, Retrofit, Core Animation, D3.js, RxSwift, REST APIs, Shopify API

Tools

Xcode, Aptana, GitHub, Interface Builder, Google Analytics, Crashlytics, Android Studio, Instabug, Auth0, Git, Calabash, Optimizely, JSX

Frameworks

iOS SDK, UIKit, XCTest, Combine, SwiftUI, Android SDK, Django REST Framework, Django, Core Data, React Native

Languages

Objective-C, Java, Swift, Python, JavaScript, GraphQL, SQL, CSS, HTML

Paradigms

Scrum, Agile Software Development, Kanban, Model View ViewModel (MVVM), Model View Controller (MVC), Mobile Development, Refactoring, VIPER Architecture, Agile

Platforms

iOS, Android, Bitrise, Firebase, Salesforce, Contentful, Shopify

Storage

JSON, MySQL, PostgreSQL

Other

GitFlow, Pull Requests, Mobile App Development, Mobile Apps, Mobile UX, Mobile UI, MessageKit, Data Visualization, Push Notifications, Cortexica, User Interface (UI), Animation, SDKs, Bluetooth, User Experience (UX), Communication, Computer Science

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