Diogo de Campos Nunes, Developer in Porto, Portugal
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Diogo de Campos Nunes

Verified Expert  in Engineering

Software Developer

Porto, Portugal
Toptal Member Since
April 18, 2014

Diogo is a mobile engineer with broad experience and deep knowledge of all things iOS. Hard-working, very efficient, and with unmatched attention to detail, he has a very positive attitude and works well both alone and in teams of various sizes. He has delivered many projects for millions of users, for both startups and big companies.


Swift, SwiftUI, Kotlin, Kotlin Multiplatform, Redux, Mobile, iOS SDK, iPhone
Canvas Medical
RxSwift, Cocoa, SwiftUI, Swift, Mirth Connect, REST, Mobile, iOS SDK, iPhone
Google APIs, In-app Purchases, Mobile Payments, Stripe, Swift, Recording...




Preferred Environment

Swift, Git, Xcode, iOS

The most amazing...

...apps I've developed were all about custom UI components, animations, and details that created a fantastic user experience.

Work Experience

Senior iOS Developer

2022 - PRESENT
  • Spearheaded the implementation and integration of complex business logic in KMM for the SumUp POS iOS app, resulting in improved scalability and increased efficiency in future development efforts.
  • Integrated successfully over 100 different printer models from various manufacturers on the SumUp POS, increasing compatibility and functionality for users worldwide.
  • Developed an iOS SDK for the Fivestars Loyalty program integration into the SumUp POS, resulting in improved user experience and increased client revenue.
  • Collaborated effectively with the integrations, daily operations, hardware, and transaction teams at SumUp, ensuring timely and accurate resolution of technical issues and smooth communication across groups.
Technologies: Swift, SwiftUI, Kotlin, Kotlin Multiplatform, Redux, Mobile, iOS SDK, iPhone

Senior iOS Developer

2021 - 2021
Canvas Medical
  • Implemented a medical app that allows practitioners to login into their hospital instance (Canvas Sandbox).
  • Developed a way for practitioners to check their appointments and patient list daily.
  • Established a shortcut system using QR codes to allow practitioners to update patients' information faster.
  • Developed a dictation feature (HIPAA compliant) that transcribes what practitioners dictate about their patient's medical information and allows them to update the current medical chart with that text.
Technologies: RxSwift, Cocoa, SwiftUI, Swift, Mirth Connect, REST, Mobile, iOS SDK, iPhone

Freelance Senior iOS Developer

2020 - 2020
  • Created an Instagram stories-like feature that has live streaming, video, and images. Text overlays were also implemented, allowing user interactions like increasing font size with a pinch, rotation, panning, and more.
  • Developed interactive pins and map popups where each user or business would have a personal banner on the top of their head. Image, video, item, or live streaming.
  • Applied stripe as a payment option for products and developed the entire checkout system for the iOS side of the app.
  • Implemented a chat that allows users and businesses to communicate through features such as sending text, images, videos, gallery items, menu items, and product lists.
  • Helped implement the virtual billboards feature in AR mode.
Technologies: Google APIs, In-app Purchases, Mobile Payments, Stripe, Swift, Recording, LiveStream, AVFoundation, RxSwift, APIs, Maps, Augmented Reality (AR), iOS, SwiftUI, Mobile, iOS SDK, iPhone

Freelance Senior iOS Developer

2020 - 2020
Sjogren's Tracker
  • Built the Sjogren's Tracker app from the ground up using Swift 5. Sjogren's Tracker an app that allows you to manage your chronic condition by tracking your symptoms, medication intake, and aggravators.
  • Designed and implemented all the back end using Firebase.
  • Built cool and reusable view components to be applied all across the app like data selectors, date pickers, cells, and more.
  • Created visual representations for data using charts, reports, insights (helpful statistics, and summaries of your flares).
Technologies: Firebase iOS SDK, Firebase, Xcode, Sketch, Zeplin, Swift, iOS, Mobile, iOS SDK, iPhone

Freelance iOS Developer

2020 - 2020
  • Helped to create an eCommerce app for the agricultural culture in LA.
  • Created reusable elements to be used all around the app.
  • Helped to improve the speed of development creating a lot of controllers and screens to the MVP in a short amount of time.
Technologies: RxSwift, Swift, iOS, SwiftUI, Mobile, iOS SDK, iPhone

iOS Developer

2019 - 2020
Switch Four
  • Worked as a developer in the team that delivered the Worktrip application to the App Store.
  • Developed a platform where we give event attendees real-time access to all event information.
  • Followed MVVM best practices, using XCTest for test cases and Bitrise for fully automated continuous integration.
Technologies: Bitrise, Zeplin, iOS, Swift, Mobile, iOS SDK, iPhone

iOS Developer (Contract)

2018 - 2019
LVMH - Moët Hennessy Louis Vuitton
  • 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.
  • 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, iOS, Swift, Mobile, iOS SDK, iPhone

iOS Developer

2011 - 2019
Glazed Solutions
  • Developed a social discovery and messaging app, Pickee.
  • Designed and implemented a Core Data database and a complex server-client offline-online syncing.
  • Created solutions to improve and optimize open connections to a web service.
  • Designed and developed a filter for messages and people, based on categories and user preferences.
  • Created a user-to-user recommendation system.
Technologies: Firebase, Git, Objective-C, iOS, Mapbox, Mobile, iOS SDK, iPhone

iOS Developer

2016 - 2017
Beacinsight (via Toptal)
  • Developed the data model and the app 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 the app's user interactions and design.
  • Implemented different algorithms to enhance the reliability of the iBeacons signal and its interaction with the app's events/logic.
Technologies: BlueCats, Swift, iOS, Mobile, iOS SDK, iPhone

iOS Developer (Contract)

2015 - 2015
  • Led the development of the brand’s main online shopping app.
  • Implemented prototype versions for the design sprints during discovery and product development phases.
  • Implemented bleeding-edge UI/UX patterns and animations.
  • Worked in short iterations with the client and a multidisciplinary team.
Technologies: Git, Objective-C, iOS, Mobile, iOS SDK, iPhone

iOS Developer (Contract)

2014 - 2015
Rocksauce Studios
  • Developed a lot of new applications for different clients, including BeerPong, Boat Day, Don't Mess with Texas, Knod, Prophit, Raison, Randid, Topshelf, TruckFood, Uslikey, and WIN Learning.
  • Dealt with a lot of client/developer interactions, app updates, and more.
  • Worked with new and custom controls for iOS.
  • Developed some in-house code for reuse.
  • Met and worked a lot of new people, including designers, web developers, API developers, and marketing.
Technologies: iOS, Objective-C, Mobile, iOS SDK, iPhone

iOS Developer (Freelance)

2013 - 2014
Thing Pink – Digital & Mobile
  • Developed "We Are on a Boat," a social sharing app about boats.
  • Developed the new version of n-Receitas for Nestle, an app about recipes and all type of cook tools (iPhone/iPad).
  • Implemented beautiful mobile layouts and developed some cool animation effects.
  • Created reusable controls (e.g., a shopping list, a conversion wheel, a step slider).
  • Developed iOS libraries for different uses. (e.g., a caching/offline support library).
Technologies: Git, Objective-C, iOS, Mapbox, Mobile, iOS SDK, iPhone

iOS Developer (Freelance)

2013 - 2013
4D Pipeline
  • Worked on two iOS applications for Nemetschek/BimPlus: bim+ Explorer and bim+ Connect (iPhone/iPad).
  • Worked with Ogre 3D C++ engine to display 3D models.
  • Worked with several people around the world, in different time zones.
  • Designed and created several UI controls to improve the back-office user experience.
  • Worked on a 2D Version of the bim+ Connect.
Technologies: TestFlight, Git, Objective-C, iOS, Mobile, iOS SDK, iPhone

iOS Developer (Freelance)

2013 - 2013
Innovation Makers
  • Developed an iOS application for Lisbon Municipal Council. (iPhone).
  • Created a QR code-based game.
  • Implemented a social quiz game using gamification features that would unlock with the player's skill level.
  • Used an MVC code structure and a Core Data model.
  • Created routing between geographic locations and geometric overlays using MapKit.
Technologies: Adobe Photoshop, Git, Objective-C, iOS, Mobile, iOS SDK, iPhone

iOS Developer (freelance)

2012 - 2013
Load Interactive
  • Developed an iOS (iPhone and iPad) application for Sony Music to display music charts and artist information.
  • Developed an iPad feature-complete multi-document (PDF) reader for KPMG.
  • Developed an iPad application for Sanofi, a customized version of the document reader.
  • Worked on an existing iOS application, Braintoss, improving the code maintainability and developing new features.
  • Trained other developers in iOS and Objective-C.
Technologies: TestFlight, Git, Objective-C, iOS, Mobile, iOS SDK, iPhone

iOS Developer (Contract)

2010 - 2011
  • Developed a framework with chemistry math methods for enterprise use.
  • Developed an app called Dew Point, which calculates saturation and temperature pressures for a fluid.
  • Developed two apps called Gas/Liquid Mixtures, which calculate gas and liquid mixtures' complex properties (viscosity, density, thermal conductivity, compressibility factor).
  • Created and specified the product architecture.
  • Wrote the paper: "Architecting and Engineering Applications on Mobile Platforms."
Technologies: iOS, Objective-C, Mobile, iOS SDK, iPhone

Sjogren's Tracker

The app allows you to customize your symptoms, medications, and aggravators that you believe trigger flares. The app will then generate a graphical display that enables you to visualize your flares as orange spikes. Other factors are graphed alongside, with an explanation underneath to help you interpret your data. Over time, the app will also generate useful statistics related to your symptoms and aggravators and summarize your flares' frequency and length. Finally, the app keeps track of your medication intake and helps you identify recurrent triggers.

The goal of this app is to help users better manage their chronic conditions. Although there is no cure for these conditions, being aware of triggers can help users avoid or anticipate flares. We hope that this app will help users better manage and plan their lives around their chronic conditions by collecting and drawing correlations from user data.


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

ASOS - Discover Fashion Online

An iOS app full redesign for the British online fashion and cosmetic retailer ASOS. During one month, a team of experts worked together in London at USTWO headquarters to create and develop ideas and concepts for the new ASOS app.

n-Receitas Nestlé

n-Receitas NESTLÉ is an application for those who like to cook, share, and learn new tricks and tips. Here, you will find recipes for all occasions, never forgetting the healthy and nutritional side of the kitchen.

Find different recipes for every day, preparation on video, tricks and tips, information on nutrition (food of the week) and thoughtful features and tools to facilitate your daily life.

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.

Tag Heuer. Celine, Dior, and Bulgari were some examples of apps that were created using this platform.

We Are on a Boat

A boat sharing app. We match people who would like to be on a boat with people who are willing to share their boat, all in real time.


bim+ Explorer - The Simplest Way to Visualize and Share Building Information Models

bim+ Explorer simplifies your daily work in the building industry. Get work done and present your project wherever you are. On-site, in the office, or on the go: all your building information in one place. Plus, it has never been easier to stay in sync with clients and colleagues.

bim+ Connect - The Simplest Way to Collaborate and Connect Building Information for Architects, Engineers, Building Managers, and House Owners

bim+ Connect allows you to quickly post project-specific information within building information models directly from your iPad. Use the Spots feature of bim+ Connect to attach questions, photos, issues or other data to any detail of your building information model or object on the bim+ platform. Have your partners alerted instantly about your “Spots” to ensure quick, reliable resolution of issues and rapid decision-making.


Speak, photograph, or write your ideas and Braintoss will send them to your email box. Audio and image messages are also interpreted and sent as text. There is also the functionality to scan business cards, which are automatically converted in a vCard.

KPMG Magazine

Digital magazine developed for iPad to present annual reports of KPMG company, a global leader in auditing, fiscal, and consulting services.

Updated through a proper CMS with the asset of reproducing multi-format contents inside it.

Sony Music

Sony's primary need was to control the worldwide rankings of the music industry. Despite all the information available about this subject, it is all dispersed, which makes it impractical to monitor and analyze the industry.

Load created a tool that aggregates information from the most important content providers (Spotify, iTunes, Youtube, Last.FM, etc.) making it available in a systematic way, by country, in a top 100 ranking. At every moment, Sony Music has in its possession all artists, music, and album movements as well as their evolution through time.

Also, biography, videos, audio samples, etc., are available for each entry of the ranking, making all the analysis process not only fast but also enjoyable and enriching.

Sanofi Store

A platform oriented toward commercial presentations, with an iPad front-end and web content manager, which enables access to documents with updated technical and scientific information. This platform organizes this content according to the different clinical specialties including scientific papers, clinical studies, official reports, statistics, and product presentation.

The platform allows dynamic management of all information, by creating user profiles and allowing only the specific user to access their respective documents safely.


Pick.ee is your new local social app! Find out who's around you and interact with people that may share interests with you | Control your privacy - choose who you see and who sees you | Pure communication (no strings attached)! | Be yourself or superman! | Create your own instant groups (open or closed) | Be pick.ee!

Menos É Mais

iOS application for Lisbon Municipal Council that allows the user to follow city routes, check news about their local councils, play some games to learn cool stuff about Lisbon, etc. To be released. (iPhone)

FedEx Golf Fan

A social website based on golf teams that play Fedex Golf Cup. Every team has one leader and three players. Each descendant can be a leader of their own team. Send items by FedEx Mail and gain FedEx points—the more points you make, the more golf-related prizes you will get.


Prophit is accounting in its purest form. It is a simple application that allows users to calculate sales price, cost basis, gross profit margins, markup, and even monthly sales reports right on your phone.

Boat Day

Browse boats using your custom search filters. Fun, fishing, watersports and more, the app shows you Boat Days when and where you need one.


Raison goes beyond reminding you what to do. It reminds you why you do it. Whatever inspires you—whatever drives you to do what you were meant to do in life—Raison will remind you of it and keep you on course.


A picture is worth a thousand views. Sending and receiving Randids is totally serendipitous—that's part of the fun—but there's still a way to share with your friends. "Favorite" the pictures you like and your Facebook friends will see the kinds of random pictures you're getting. Beautiful sunsets, eye-catching landscapes, and artistic masterpieces.


The future of alcohol delivery…is here.

TopShelf is a streamlined way to order alcohol from the palm of your hand. We aim to bring the highest quality and convenience for getting liquor, wine, and beer delivered to YOU.

TopShelf seamlessly connects users to local liquor stores in their area. Alcohol delivery can be used for corporate events, tailgating, weddings, parties, the casual nightcap, and so much more.

Place your order, track your delivery, sit back, and relax. Alcohol delivered in under 60 minutes.


Truckfood allows you to find the best food trucks in your area. Now with seven new major cities, you can get the best grub anywhere.

Want burgers? Simply click the Cuisine button to find all the burger trucks!

Bookmark and rate your favorite trucks. Share your truck love with others now with social media postings!

We hope you love the app, as much as you love the food!

Us Likey

Have you ever agonized over trying to pinpoint someone’s “taste” or guess what they like or would like to have? Have you ever been amazed at how little those closest to you really know about the small details?

Us Likey is a place where you can create and share your personalized collection focused ONLY on the specific consumer products, places, styles, brands, foods, gadgets, music, movies, hobbies, and everything else that define you. Share all the specific details about your personal preferences—everything from your favorite brand and flavor of ice cream or favorite restaurant or the type of perfume you wear!

Us Likey allows you to discover new products and places while you receive recommendations from the people you trust most—your friends! Share what you buy, what you want, what you like, and what defines your taste.

WIN Atlas: Career Planning and Exploration

WIN Atlas makes planning and exploring for a career path engaging, relevant, and exciting. Users of the mobile app can begin with a quick selection of three primary options: 1) I just can’t narrow it down; 2) I know what I want to be; 3) I have no idea what I want to be. From this initial question, students can quickly and easily engage in narrowing their career interests and plan for the road ahead.


WorkTrip is a web-based and mobile software solution that serves as a centralized hub to communicate all of your event and travel details. Quickly access detailed information related to your next trade show, meeting, or event, such as agendas and documents, along with your detailed travel reservations for that event.
2011 - 2014

Bachelor's Degree in Production and Music Technology

ESMAE - Music and Arts School - Porto, Portugal

2006 - 2011

Master's Degree in Informatics Engineering

Faculty of Engineering, University of Porto - Porto, Portugal


Instagram API, X (formerly Twitter) SDK, Facebook iOS SDK, RxSwift, Firebase iOS SDK, iOS Charts, Stripe, Google APIs, Parse SDK, CocoaPods, Google Analytics API, Alamofire, Facebook SDK, Google Maps SDK, Fabric, Mirth Connect


Xcode, Google Analytics, SourceTree, Crashlytics, Git, TestFlight, Zeplin, Sketch, Adobe Photoshop, Eclipse IDE, Microsoft Visual Studio, GitHub, Trello, Slack, Jira


SwiftUI, iOS SDK, Core Data, UIKit, MapKit, ImageIO, AudioToolbox, Cocos2d, OGRE, Combine, Box2D, AFNetworking, Cocoa, Redux


Swift, Objective-C, C++, C, Java, XML, SQL, PHP, HTML5, CSS, UML, Kotlin


MacOS, iOS, Mobile, Firebase, Linux, Bitrise, Mapbox


JSON, SQLite, MySQL, PostgreSQL


Model View ViewModel (MVVM), Scrum, Agile Software Development, Kanban, Model View Controller (MVC), Management, Object-oriented Programming (OOP), REST

Industry Expertise



Spotify, iPhone, Mobile App Development, Algorithms, BlueCats, 3D, Education, Educational Games, Student Engagement, Lifestyle, Augmented Reality (AR), Charts, Reports, Statistics, Medical Coding, User Experience (UX), PDF, Ebooks, Events, Maps, APIs, AVFoundation, LiveStream, Recording, Mobile Payments, In-app Purchases, Pull Requests, Kotlin Multiplatform

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