João Dias Barbosa

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

Hire João

Portfolio

Glazed Solutions
iOS, Android, Objective-C, Java, Django, Python
Small Planet
Java, Objective-C
Beacinsight
iOS, Swift, BlueCats beacons

Experience

Java, 5 years
Android, 4 years
Android SDK, 4 years
Python, 3 years
iOS SDK, 3 years
iOS, 3 years
Parse SDK, 2 years
Swift, 1 year

Availability

Part-time

Preferred Environment

iOS, Android, Xcode, Android Studio, Git

The most amazing...

...app 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.

Employment

Mobile Software Engineer
2012 - PRESENT
Glazed Solutions
- Brought many iOS and Android apps from concept to the App Store.
- Created wireframes, and 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: iOS, Android, Objective-C, Java, Django, Python
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: Java, Objective-C
iOS Developer
2015 - 2016
Beacinsight
- 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: iOS, Swift, BlueCats beacons
iOS Developer
2015 - 2015
Keepy
- 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: iOS, Objective-C
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
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: Java, Swift
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 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: Objective-C, Python, Django REST Framework
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: Java, Python, Django REST Framework
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 authentication system, allowing both Facebook and email registration, and the notification system.
- Created wireframes, and redesigned UX and navigation flows.
Technologies: Objective-C, Python, Django REST Framework
Mobile Engineering Intern
2012 - 2012
Glazed Solutions
- Worked on a big-data 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.
- Contributed new visualizations to the D3.js framework.
Technologies: iOS, PhoneGap, HTML5, JavaScript, CSS, Objective-C, Data Visualization, D3.js
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: Android, Java

Experience

Treasured (Development)
http://treasured.com
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 chidren to be shared with friends and family.
Beacinsight (Development)
http://beacinsight.io/
A healthcare workflow application for clinicians and administrators. Using iBeacons to track the users location, it's 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 patients 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.

Skills

Languages
Java, Objective-C, Swift, JavaScript, Python
Frameworks
iOS SDK, Android SDK, Django
Libraries/APIs
Twitter API, Facebook API, Mixpanel API, Butterknife, Parse SDK, Retrofit, Foursquare API, Google AdWords
Tools
Xcode, Aptana, Eclipse IDE, Android Studio, Google Analytics, Crashlytics, TextMate
Paradigms
Scrum, Agile Software Development, Kanban
Platforms
Android, iOS, Linux
Other
EventBus
Storage
PostgreSQL, MySQL