Senior iOS/Swift Developer
2022 - PRESENTSwift Medical Inc.- Worked on a cutting-edge and innovative healthcare app with a device called Sinatra, connected to the phone via BLE, which takes and analyzes photos of wounds and aids doctors and nurses in tracking progression.
- Worked on all aspects of the app, as well as created a standalone app that helped the team provision the Sinatra devices.
- Completed new features of the app, such as working on bacterial analysis, single-form evaluation, and other thermal imaging analysis for the app.
Technologies: Swift, Core Data, iOS, Bluetooth, AVCapture, Leadership, Video Capture, UX, SwiftUISenior iOS Developer
2021 - 2022Catapults Sports LLC- Worked on instrumental in the live streaming of this sports app, syncing multiple angles to stream effortlessly as the user went from angle to angle.
- Managed the entire CI/CD pipeline, Apple Store account, and release process as a sole developer.
- Fixed numerous issues, usually around video editing, and implemented a caching layer to make streaming more efficient for very long videos and potentially slow internet connections.
Technologies: Objective-C, iOS, C++, C#, JavaSenior iOS Developer
2019 - 2020Anthem, Inc.- Helped design the navigation bridge between the iOS-embedded navigation stack and the React Native navigation scheme.
- Worked on device integration; the app tracked steps, sleep, and weight through syncing with HealthKit and more.
- Built accessibility to comply with all federal regulations.
- Provided unit testing and automated builds with Jenkins pipelines.
- Developed push notifications with embedded rich content inside the messages.
Technologies: Kotlin, Java, Objective-C, React Native, SwiftSenior iOS Developer
2015 - 2020AutoLoop, LLC- Leveraged gelocation for marketing purposes.
- Wrote an entire UI and unit test suite.
- Wrote scripts in Fastlane to fully automate the release—perform screenshots, run all tests, and make releases.
- Built custom UI and animation.
- Wrote an app to facilitate the check-in procedure for car dealers.
Technologies: Objective-CiOS Developer
2019 - 2019Latch- Helped with the reskinning of the UI for the release.
- Worked on debugging issues with Bluetooth connection using BLE protocol.
- Created custom UI components, like piecharts using Core Graphics.
Technologies: Carthage, Core Data, Swift, iOS, Bluetooth LESenior iOS Developer
2015 - 2019Max2, Inc.- Worked on a payment module that required Bluetooth interfacing with hardware.
- Formatted ISO 8583 messages intended to securely process payments.
- Developed a chat module leveraging web sockets.
- Worked with remote and in-app notifications.
- Worked with Twitter, FB, and Instagram SDKs. The app promotes social media interactivity.
- Built a custom UI.
- Wrote an app that allows users to search for, view, and rate venues as well as purchase items and do transactions.
Technologies: Objective-C, SwiftiOS Developer
2015 - 2015Stand Technologies- Oversaw this project for a small stand-up company from development to release on the App Store.
- Implemented push notifications, including writing server-side code.
- Created a custom networking layer, including efficient categories for image caching and setting UIImageViews, with the ability to cancel or reuse requests if the UIImageView would happen to be reused (such as in a reusable cell) using associated objects.
- Used Facebook APIs for login.
- Created a custom newsfeed using dynamic row heights for added flexibility.
Technologies: SwiftSenior iOS Developer
2015 - 2015Roomi- Integrated Parse and Layer to build native chat into the app.
- Worked with Core Animation, Core Text, and CALayer to customize the user experience.
- Used advanced techniques, such as object swizzling, to override default behavior and enhance functionality.
- Worked with Parse's cloud and developed and maintained scripts in JavaScript.
- Worked extensively with push notifications.
Technologies: Core Animation, Parse, Objective-CiOS Developer
2014 - 2015Best Buy- Redesigned and rewrote the entire Best Buy app in Swift.
- Architected the app based on the VIPER paradigm.
- Made use of new Apple technologies such as app extensions and their widgets, primarily for advertisements.
- Experimented with iBeacons. Best Buy was one of the first stores to embed iBeacons into their department store lighting.
- Began working on Apple Pay for a more seamless checkout experience using the Best Buy app.
- Replaced the zBar scanner with a native Apple scanner for barcodes.
- Implemented fast image caching across the application.
Technologies: SwiftSenior iOS Developer
2014 - 2014ConXus Lochinvar- Redesigned the UI to look appropriate for the iPhone. Previous developers had only paid attention to the iPad.
- Gained extensive experience with auto layouts of all forms.
- Worked with the Microsoft Cloud and Azure.
Technologies: iOSiOS Developer
2013 - 2014Target (Cartwheel)- Worked on implementing a highly automated environment. Employed a dedicated Jenkins server and Xcode bots and hooks so every Git checkin for the QA would get the latest build to Test Flight.
- Worked with Crashlytics for bug tracking.
- Worked with true Agile methodologies and Jira for efficient work progress.
- Worked extensively with PassKit and CocoaPods.
- Made extensive use of OAuth tokens to guard sessions for items added to cart, as well saved payment information (each having their own tokens).
- Used Google Postman to debug and document RESTful APIs.
Technologies: Objective-C, iOSiOS Developer
2012 - 2013Rockwell Collins- Made extensive use of MapKit and Waypoints for plotting airplane itineraries.
- Made a custom calendar from UICollection View.
- Made extensive use of core data as a kind of cache for data, including using helpful third-party tools like Mogenerator.
- Implemented extensive security features, such as storing in the keychain and various hashing and encryption algorithms.
- Used regular expressions for input validation to prevent SQL injections.
Technologies: Objective-C, iOS
Software Architecture Developer in Miami Beach, United States
Member since June 21, 2015
Stefan is a highly skilled iOS developer with a master's degree in physics. He loves both technological and artistic sides of software engineering. He has had the pleasure to work on some popular enterprise-level apps used by millions of people for companies like Target, Best Buy, and Roomi. He believes that app development is truly an art.
Stefan is now available for hire
Portfolio
- Swift Medical Inc.Swift, Core Data, iOS, Bluetooth, AVCapture, Leadership, Video Capture, UX...
- Catapults Sports LLCObjective-C, iOS, C++, C#, Java
- Anthem, Inc.Kotlin, Java, Objective-C, React Native, Swift
Experience
- Objective-C 8 years
- iOS 7 years
- Swift 5 years
- Bluetooth LE 4 years
- Java 3 years
- Software Architecture 2 years
- Kotlin 1 year
Availability
Full-time
Preferred Environment
Objective-C, Swift
The most amazing...
...app I've developed was Cartwheel for Target, an app that has touched so many people.
Employment
Experience
- Cartwheel App
A social savings app for Target. I was one of two developers who rewrote Cartwheel away from the original code base, which was owned by Deloitte. Cartwheel is used by millions of people across the USA.
- Best Buyhttps://itunes.apple.com/us/app/best-buy/id314855255?mt=8
This is the Best Buy store shopping experience app. I was the lead architect in the Swift redesign of the Best Buy app, employing the VIPER paradigm. The project included experimentation with iBeacons and Apple Pay.
- SmartLanehttps://itunes.apple.com/us/app/smartlane/id686173091?mt=8
A dealership app that I am currently maintaining for AutoApp. It is used in Mercedes and Toyota dealerships all across the USA. It allows you to check in and have service on your car, all from the convenience of an iPad.
- Ascend Flight Managerhttps://itunes.apple.com/us/app/flight-manager/id469557418?mt=8
Manage your private jet with this convenient app! This app allows you to create custom flight plans for your private jets. I was the sole developer on this app. It features an immense focus on security, as his clientele base consists of executives for large companies like Coca Cola. I explored the depths of security provided by the Apple OS and was tasked with adding my own custom security options.
- Roomihttps://roomiapp.com
A app to help people find roommates in cash-expensive markets such as New York City and San Francisco, this app facilitates in-app chat (which I personally developed), paying rent through the app, and browsing room listings
- STAND
A social fundraising app to help motivate positive change around the world. Start your own fundraising stands and get your Facebook friends as well as others in the loop. Watch as money is raised for your favorite projects.
- Senior Software Developer for Max2
Developed their merchant facing app for iOS in Swift. Worked on the payment module, leveraging Bluetooth, securely formatting messages (using ISO 8583) to securely process payments, app notifications, leveraging websockets, and more.
- LATCHhttps://apps.apple.com/us/app/latch-app/id1062355375
Developed the UI for Latch App including app interfaces (via BLE protocol) with hardware locks that control access to doors for individual customers and businesses alike. I was part of the team that redesigned and implemented a re-branding and new UI.
- iOS Animation and Tuning for Efficiency (Publication)Smooth animations and flawless transitions are key to perceived performance in modern mobile applications. Without the right tools, tuning iOS animation for efficiency can be a challenge in itself. In this article, Toptal engineer Stefan Progovac demonstrates the role of Instruments, a sophisticated set of performance profiling tools for iOS, discussing how they can help you understand animation performance bottlenecks and some strategies for working around them.
Skills
Languages
Swift, XML, Objective-C, JavaScript, Kotlin, Java, Python, C++, C#Frameworks
OAuth 2, AFNetworking, Core Data, SwiftUI, FlutterLibraries/APIs
CocoaPods, Parse SDK, Layer API, Apple Maps API, Kiwi, Mantle, Google API, Facebook SDK, jQuery, Core AnimationTools
Hockey SDK, Crashlytics, GitHub, Git, Jira, Xcode, Slack, Apple Push Notifications, Suds, Pivotal Tracker, AsanaParadigms
Agile Software Development, Mobile DevelopmentPlatforms
Bluetooth LE, iOS, Apple Watch, Firebase, ParseStorage
JSONOther
OAuth, Geolocation, Programming, Freelance, IT, Software Architecture, Machine Learning, Augmented Reality (AR), Carthage, Bluetooth, AVCapture, Leadership, Video Capture, UX
Education
- Master of Science Degree in Physics2009 - 2012University of California San Diego - San Diego, USA
- Bachelor of Science Degree in Mathematics2005 - 2009Michigan State University - East Lansing, USA
