Stefan Progovac - Freelance Objective-C Developer for Hire

Senior iOS Developer

2015 - PRESENT

Max2, 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: Swift, Objective-C

Senior iOS Developer

2015 - PRESENT

AutoLoop, 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-C

iOS Developer

2015 - 2015

Stand 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: Swift

Senior iOS Developer

2015 - 2015

Roomi

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: Objective-C, Parse, Layer

iOS Developer

2014 - 2015

Best 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: Swift

Senior iOS Developer

2014 - 2014

ConXus 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: iOS

iOS Developer

2013 - 2014

Target (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: iOS, Objective-C

iOS Developer

2012 - 2013

Rockwell 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: iOS, Objective-C

Cartwheel App (Development)

A social savings app for Target. Stefan 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 Buy (Development)

https://itunes.apple.com/us/app/best-buy/id314855255?mt=8

This is the Best Buy store shopping experience app. He was the lead architect in the Swift re-design of the Best Buy app, employing the VIPER paradigm. The project included experimentation with iBeacons and Apple Pay.

SmartLane (Development)

https://itunes.apple.com/us/app/smartlane/id686173091?mt=8

A dealership app that Stefan is 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 Manager (Development)

https://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. Stefan 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. He explored the depths of security provided by the Apple OS and was tasked with adding his own custom security options.

Roomi (Development)

https://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 Stefan personally developed), paying rent through the app, and browsing room listings

STAND (Development)

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 (Development)

https://www.veea.com/

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 web sockets, and more.

iOS Animation and Tuning for Efficiency (Publication)

https://www.toptal.com/ios/ios-animation-and-tuning-for-efficiency

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.

Languages

Swift, Objective-C, XML, Python, Java, JavaScript

Frameworks

OAuth2, AFNetworking, Core Data

Libraries/APIs

CocoaPods, Apple Maps API, Layer API, Parse SDK, Facebook SDK, Google API, Mantle, Kiwi

Tools

Crashlytics, GitHub, Git, JIRA, Xcode, Apple Push Notifications, Slack, Hockey SDK, Suds, Pivotal Tracker, Asana

Paradigms

Agile Software Development

Platforms

iOS, Firebase

Other

OAuth, Geolocation

Master of Science degree in Physics

2009 - 2012

University of California San Diego - San Diego, USA

Bachelor of Science degree in Mathematics

2005 - 2009

Michigan State University - East Lansing, USA