
Strahinja Mihajlovic
Verified Expert in Engineering
ChatGPT API Developer
Belgrade, Serbia
Toptal member since December 10, 2019
Strahinja Mihajlovic is an iOS developer with eight years of experience delivering innovative mobile apps. Specializing in Swift and SwiftUI, he creates clean, user-focused designs. His AI-powered note-taking app, featuring an interactive chat interface, improved user retention by 40%. Strahinja has also built scalable solutions for telecommunication and healthcare clients, driving engagement and optimizing workflows with impactful results.
Portfolio
Experience
- Swift - 8 years
- SwiftUI - 6 years
- Combine - 6 years
- Model View ViewModel (MVVM) - 6 years
- SQLite - 4 years
- VIPER Architecture - 3 years
- ChatGPT API - 3 years
- Clean Architecture - 3 years
Availability
Preferred Environment
Xcode, MacOS, Figma, Mobile App Development, Large Language Models (LLMs), OpenAI, Mobile Applications, iOS SDK
The most amazing...
...project I’ve developed is a chat feature that lets users interact with their notes through AI.
Work Experience
iOS Developer
Mem
- Developed an in-app note-taking editor with markdown, comments, links, media files, and more.
- Created a share sheet for the app, which handles image sharing, text sharing, and URL sharing.
- Built almost 100% of the app using only SwiftUI components.
iOS Developer
DeepScribe (via Toptal)
- Developed a view that represents live audio input in the form of sound waves.
- Contributed to a Mac Catalyst app and developed complex UI components that worked on both iPad and Mac.
- Developed and implemented a complete network layer supporting older API calls.
iOS Developer
In the Barn (via Toptal)
- Rewrote the entire application storyboards to support all mobile and iPad devices.
- Implemented Google, Apple, and Facebook sign-in methods.
- Designed and developed ad listing pages for many different ad categories.
- Implemented native APIs such as geolocation, background fetching, and background uploading.
- Set up a new architecture to clear the technical debt and established tests and documentation.
iOS Developer
Wireless Media
- Developed many telecommunication applications for the Balkan region.
- Rewrote the entire network layer to a SAP back end.
- Built a custom library for galleries that, apart from photos, supports native video content, YouTube videos, ads, custom views, and more.
- Developed a custom library for location services that provides an easy way to work with location-related functionalities.
- Created a mechanism for theme switching on an existing application that works with a system theme and allows other developers to support light and dark-themed versions of future views with ease.
- Analyzed and later created a plan for analytics that was implemented by the entire mobile team.
- Developed an entire application in the Combine framework.
- Created an entire bill payment process that communicates with the bank for telecommunication applications.
- Developed complex registration processes that worked seamlessly with deep linking and keychain.
- Handled releases of 10+ applications weekly and spent many hours talking with Apple.
iOS Developer
Camps
- Provided a framework with flexible high-level features, reducing boilerplate code to a minimum.
- Developed and optimized most of the UI elements and animations.
- Performed a high number of UI optimizations so that the app could be installed on a lot of lower-end devices.
- Designed back-end services that were later implemented in the application.
- Implemented many external libraries to speed up the development process and meet the deadline.
iOS Developer
Wireless Media
- Developed many newsreader applications for the Balkan region.
- Contributed to the complex video player, which seamlessly integrates inside news applications. It uses AVKit in basic implementation and JWPlayer in some implementations that require video ads.
- Implemented a continuous integration/continuous delivery system that works with Slack commands, which made it easier for managers/quality assurance engineers to upload builds without developers' help.
- Rewrote one of the apps entirely from Objective-C to Swift.
- Implemented deep linking, push notifications, and an ad (banner) system for external links.
- Implemented both Google (Firebase) and Gemius analytics.
- Developed a hybrid story page (for a newsreader) that is made in combination with Swift, HTML/CSS, and JavaScript.
- Built a mechanism that helps with the application localization and localization itself, as most of the applications were multilanguage.
- Designed and later developed a custom iPad version for one of the applications.
- Worked with many weather forecast APIs that were used in newsreader applications.
Experience
N1 Info
https://apps.apple.com/us/app/n1-info/id920779491Mondo
https://apps.apple.com/us/app/mondo/id673090202Story Hr
Moj mts
https://apps.apple.com/us/app/moj-mts/id957823723Moj m:tel
https://apps.apple.com/us/app/moj-m-tel/id1423516571Mein Mtel Austria
https://apps.apple.com/us/app/mein-mtel-austria/id1091989686Moj m:tel
https://apps.apple.com/us/app/moj-m-tel/id1251877918Sportklub
https://apps.apple.com/us/app/sportklub/id1144073831Sasomange
Mts Biznis
https://apps.apple.com/us/app/mts-biznis/id1301211948Camps With Friends
In the Barn
Mem - AI Notes
Education
Bachelor's Degree in Software Engineering
Information Technology School - Belgrade, Serbia
Skills
Libraries/APIs
Alamofire, Firebase iOS SDK, CocoaPods, RxSwift, Lottie-iOS, Fabric
Tools
Git, Jira, Xcode, Zeplin, Crashlytics, ChatGPT, Figma
Languages
Swift, HTML, GraphQL
Frameworks
Combine, UIKit, Cocoa Touch, SwiftUI, Core Data, Core Location, MapKit, iOS SDK
Paradigms
Agile Software Development, Model View ViewModel (MVVM), VIPER Architecture, Clean Architecture, Model View Controller (MVC)
Platforms
iOS, MacOS, Firebase, Parse, Amazon Web Services (AWS)
Storage
SQLite, Firebase Realtime Database
Other
Notification Center, Push Notifications, Deep Linking, Mobile App Development, Mobile Applications, OpenAI, ChatGPT API, Location Services and Maps, Maps, Large Language Models (LLMs), Lottie, Apollo, UI Animation
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