Ivan is available for hire
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Verified Expert in Engineering
iOS Developer
Limerick, Ireland
Toptal member since January 13, 2020
Bio
Ivan is a lead iOS developer who is passionate about helping large teams manage complexity through code and process improvements. He is a proponent of clean code and TCA for SwiftUI and believes in encouraging code structures that enable experimentation. Ivan has experience leading high-performance, medium-sized mobile teams and expertise in architecture design and Agile processes, client communication, project ideation, specification, and planning.
Portfolio
Noom
Swift, iOS, Agile, Mentorship, UIKit, Git, SwiftUI, RxSwift, Objective-C...
Jostten Sackitey
Swift, iOS, Amazon Web Services (AWS), Apple Watch, PostgreSQL, OpenAI...
Pyrium, INC.
Swift, Mobile, Xcode, SwiftUI, iOS, TestFlight
Experience
- iOS - 10 years
- Swift - 8 years
- Agile - 6 years
- Objective-C - 6 years
- ARKit - 3 years
- RxSwift - 3 years
- SwiftUI - 3 years
- Management - 2 years
Availability
Part-time
Preferred Environment
Xcode, iOS, iPadOS, tvOS, ARKit
The most amazing...
...project I've led is a Noom Premium bundle that significantly improved LTV, retention, and engagement among existing and new users.
Work Experience
Lead iOS Engineer
2021 - PRESENT
Noom
- Led the mobile team in charge of meal logging and planning, with the main goal of improving LTV. Launched the Noom Premium bundle, significantly improving LTV, retention, and engagement among existing and new users.
- Used SwiftUI with The Composable Architecture (TCA) to produce fully tested and composable components.
- Helped the broader team manage tech debt, primarily by creating a plan for tech debt reduction and by pursuing SwiftUI and TCA.
Technologies: Swift, iOS, Agile, Mentorship, UIKit, Git, SwiftUI, RxSwift, Objective-C, Core ML, REST, Management, iOS SDK, iOS Native Libraries, Firebase, Firebase Authentication, Jira, Figma, Slack, Mobile Development, Architecture, Alamofire, AVFoundation, Model View ViewModel (MVVM), Mobile Apps, APIs, iOS Frameworks, Lottie, Cocoa Touch, Cocoa, iOS Video, Core Data, Mixpanel, Amazon Web Services (AWS), In-app Purchases, Mobile, Computer Vision, CocoaPods, Apple HealthKit, Apple Watch, REST APIs, User Interface (UI), TestFlight, OpenAI, WatchOS, WatchKit, WatchOS UI
Swift Developer
2024 - 2024
Jostten Sackitey
- Parsed OpenAI and Grok AI responses into workouts to match the existing domain models.
- Implemented several new features, including a fully functioning AI chatbot, workout templates, and exercise tracking.
- Improved app stability and overall UX significantly by simplifying and reusing the UI code.
Technologies: Swift, iOS, Amazon Web Services (AWS), Apple Watch, PostgreSQL, OpenAI, Apple HealthKit, Mailchimp, Mixpanel, WatchOS, WatchKit, WatchOS UI
Senior iOS Developer
2023 - 2024
Pyrium, INC.
- Delivered a mobile-first crowdfunding MVP app together with the team, which passed the FINRA approval process.
- Worked closely with product and QA to deliver a high-quality app.
- Refracted large amounts of legacy code using SwiftUI and TCA.
Technologies: Swift, Mobile, Xcode, SwiftUI, iOS, TestFlight
Senior iOS Developer
2021 - 2021
Stanley Park
- Joined after engineering work kicked off. Helped manage other engineers working on the same project and ensured everyone was aligned.
- Built iOS and iPad app that allowed users to add images and video to the canvas, transform the media and reposition it, write, and draw.
- Implemented a data storage solution, which simultaneously allowed large canvas media size while providing good performance.
Technologies: iOS, Swift, Firebase, Google Cloud, Model View ViewModel (MVVM), Figma, Mobile Apps, iOS Frameworks, Cocoa Touch, Cocoa, Mobile, CocoaPods, REST APIs, User Interface (UI)
Senior iOS Developer
2020 - 2021
Stratway Consulting Ltd.
- Developed an MVP app that allowed users to communicate with each other using video. The app supported up to four people streaming videos at a time, and others could join as spectators.
- Helped simplify and break down the initial idea into manageable chunks, which gave the owner a better understanding of the road ahead.
- Submitted app updates weekly using Firebase App Distribution. This was done using Fastlane.
Technologies: Swift, iOS, Messaging, Videos, Twilio, Model View ViewModel (MVVM), Video Livestreaming, LiveStream, Mobile Apps, APIs, iOS Frameworks, Cocoa Touch, Cocoa, Mobile, CocoaPods, REST APIs, User Interface (UI)
Lead iOS Developer
2019 - 2021
SweepBright
- Led the cleanup and refactoring of the existing application while providing new features for the existing customers.
- Reduced the number of run-time crashes by more than 95% by using a strict code style and introducing a handful of design patterns.
- Adopted many best practices in the team, including using SwiftUI and Combine, while transitioning the app to a clean architecture.
- Collaborated with the design team and rethought the app navigation, design, and user interaction.
Technologies: Facebook API, iPad, SQL, Scrum, REST, GraphQL, Git, RxSwift, Xcode, iOS, Swift, UIKit, Agile, iOS SDK, iOS Native Libraries, Figma, Slack, Mobile Development, Google Maps API, Architecture, Alamofire, AVFoundation, Realm, Model View ViewModel (MVVM), Video Livestreaming, LiveStream, Mobile Apps, APIs, Google Maps SDK, iOS Frameworks, Lottie, Cocoa Touch, Cocoa, iOS Video, Core Data, Amazon Web Services (AWS), PostgreSQL, In-app Purchases, Mobile, CocoaPods, REST APIs, User Interface (UI), TestFlight
Senior iOS Developer
2019 - 2019
Numbrs
- Improved test coverage of crucial business-related processes.
- Refactored large parts of the codebase from Objective-C to Swift.
- Collaborated with the team and discussed and implemented features related to analytics in the personal banking domain.
- Introduced a proposal to modify the architecture according to slightly modified VIPER architecture (clean architecture for iOS).
Technologies: Scrum, REST, Git, RxSwift, Xcode, iOS, Swift, UIKit, Agile, iOS SDK, iOS Native Libraries, Jira, Slack, Mobile Development, Google Maps API, Alamofire, AVFoundation, Realm, Model View ViewModel (MVVM), Mobile Apps, APIs, Google Maps SDK, iOS Frameworks, Lottie, Cocoa Touch, Cocoa, PostgreSQL, Mobile, CocoaPods, REST APIs, User Interface (UI)
iOS Developer
2017 - 2019
Freelance
- Led a team of iOS, Android, and back-end developers to fix and publish an existing iOS app. Concurrently also worked on refactoring and fixing old code while developing new features.
- Worked with a successful Croatian startup, SmartLumies, to develop a smart, Bluetooth-connected toy. Designed and developed a Bluetooth communication protocol that the app used to communicate with the toy.
- Developed an iOS application that used in-device sensors to help users understand and improve their workouts.
- Developed an iPad application primarily intended for ophthalmology. The application simplifies the process of creating, storing and distributing eye diagnoses.
Technologies: REST, Git, RxSwift, Xcode, iOS, Objective-C, Swift, UIKit, iOS Native Libraries, Figma, Slack, Mobile Development, Architecture, Alamofire, Mobile Apps, APIs, iOS Frameworks, Cocoa Touch, Cocoa, PostgreSQL, In-app Purchases, Mobile, CocoaPods, Apple Watch, REST APIs, User Interface (UI)
iOS Developer
2016 - 2017
Undabot
- Migrated Njuskalo, a large Croatian ad portal from web-based to native iOS UI.
- Collaborated on a company-wide VIPER architecture that was used on upcoming projects.
- Developed a tvOS Twitter wall application with iOS controller application.
Technologies: Xcode, iOS, Swift, UIKit, Git, Mobile Development, Alamofire, Mobile Apps, iOS Frameworks, Cocoa Touch, Cocoa, Mobile, CocoaPods, User Interface (UI)
iOS Developer
2014 - 2016
IN2 group
- Built an employee management application that included off-time, business travel, and vehicle management powered by an Oracle APEX back end.
- Worked as the first in-house iOS developer and established a base architecture, code style, and iOS workflows—some of which are used to this day.
- Collaborated on starting an iOS education process inside of the company.
Technologies: Xcode, iOS, Objective-C, Swift, Mobile Development, Alamofire, Mobile Apps, iOS Frameworks, Cocoa Touch, Cocoa, Mobile, CocoaPods, User Interface (UI)
Experience
Sweepbright
https://www.sweepbright.com/A Belgian based B2B app for real-estate agencies focused on automation. I joined the project at the start of the scale-up phase. The iOS app was running, but there were quite many issues, both code and design-wise.
My goal was to clean-up the app making it more main-stream and fixing the main code issues during this process. This effort allowed us to grow at a much greater speed by entering the French market, for which a clean and polished iOS app was one of the main movers.
Main code issues were undefined architecture that made the state very difficult to determine, heavy reliance on a very outdated third-party library, and a general lack of defined code-style and best practices.
My goal was to clean-up the app making it more main-stream and fixing the main code issues during this process. This effort allowed us to grow at a much greater speed by entering the French market, for which a clean and polished iOS app was one of the main movers.
Main code issues were undefined architecture that made the state very difficult to determine, heavy reliance on a very outdated third-party library, and a general lack of defined code-style and best practices.
Party Initiative Tracker
Work Done:
• Designed, implemented, and published an iOS app that simplifies tracking initiative for role-playing games.
• Implemented both the native iOS app and the back end using Swift Vapor.
• Hired and managed QA and design team members.
• Designed, implemented, and published an iOS app that simplifies tracking initiative for role-playing games.
• Implemented both the native iOS app and the back end using Swift Vapor.
• Hired and managed QA and design team members.
CUPUS
CUPUS is an iOS application that serves as a sensor in a publishing/subscribing communication system.
Work Done:
• Developed the CUPUS middleware for the University of Zagreb, Faculty of Electrical Engineering and Computing (FER) that implements the communication protocol with pre-filtering of the sensor data streams,
Work Done:
• Developed the CUPUS middleware for the University of Zagreb, Faculty of Electrical Engineering and Computing (FER) that implements the communication protocol with pre-filtering of the sensor data streams,
Workout App with Integrated Chatbot
A Swift-based workout app. The app allows users to create workout templates and use them to track their workouts in real time. The app integrated an LLM-based chatbot. The chatbot collects users' workout preferences and creates workout suggestions based on those preferences. The user could then use the suggestion to create in-app workouts.
Education
2015 - 2017
Master's Degree in Computer Science
University of Zagreb, Faculty of Electrical Engineering and Computing (FER) - Zagreb, Croatia
2012 - 2015
Bachelor's Degree in Computer Science
University of Zagreb, Faculty of Electrical Engineering and Computing (FER) - Zagreb, Croatia
Skills
Libraries/APIs
Firebase iOS SDK, iOS Native Libraries, RxSwift, Alamofire, SnapKit, CocoaPods, REST APIs, Google Maps SDK, Mapbox iOS SDK, Google+ iOS SDK, Google Maps API, Facebook API, Stripe
Tools
Xcode, Git, Jira, Figma, Slack, TestFlight, Apple HealthKit, Sketch, Firebase Authentication, Mailchimp
Languages
Swift, Objective-C, SQL, GraphQL
Frameworks
SwiftUI, UIKit, Core Location, iOS SDK, iOS Frameworks, Cocoa Touch, Cocoa, ARKit, Core ML, Vapor, Core Data, WatchKit
Paradigms
Agile, REST, Mobile Development, Model View ViewModel (MVVM), Scrum, Management
Platforms
iOS, Mobile, WatchOS, tvOS, Firebase, Mixpanel, Twilio, Amazon Web Services (AWS), Apple Watch
Storage
Firebase Realtime Database, PostgreSQL, Realm, Google Cloud
Other
Software Architecture, App Store, iPad, Mobile App Development, Architecture, Mobile Apps, In-app Purchases, User Interface (UI), Maps, Mobile GPS, GPS, Cloud, Google Login, Encryption, AVFoundation, Video Livestreaming, LiveStream, APIs, Lottie, iOS Video, WatchOS UI, Mentorship, Messaging, Videos, Computer Vision, OpenAI
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