Dino is available for hire
Hire DinoDino Bartošak
Verified Expert in Engineering
Mobile Architecture Developer
Zagreb, Croatia
Toptal member since June 29, 2016
Bio
As a software engineer with more than a decade of experience in IT, Dino has specialized his skills in building mobile apps. He has worked with teams of various sizes and has developed skills in building products iteratively. He has also developed analytical abilities and prototyping techniques. Dino likes clean, modular, and maintainable code written to be reliable in all conditions. iOS is his platform of choice.
Portfolio
Mediflix, Inc.
UIKit, iOS, Swift, Xcode, iOS Instruments, Accessibility, Video Streaming...
Circular, LLC
Swift, iOS, Firebase iOS SDK, Firebase, Xcode, iOS Instruments, UIKit...
Jumprope, Inc.
Swift, Xcode, iOS Instruments, AVFoundation, UIKit, RealmSwift, GraphQL...
Experience
- REST - 12 years
- Object-oriented Programming (OOP) - 12 years
- Xcode - 10 years
- Git - 10 years
- iOS - 10 years
- Mobile Architecture - 8 years
- Swift - 8 years
- Model View ViewModel (MVVM) - 6 years
Availability
Part-time
Preferred Environment
Git, Swift, Xcode, iOS, Slack, MacOS
The most amazing...
...thing I've made is LooksGood, an app built from scratch, full of subtle UX details and animations which make the app a pleasure to use.
Work Experience
iOS Developer
2023 - 2023
Mediflix, Inc.
- Created a TikTok-like vertical paginated video player with streamed video content and iterated through it as designs changed. Made sure to make code modular so that new designs could be implemented and tested smoothly.
- Implemented a chat feature where I created a messaging module for message send and receive with optimized and paginated message loading. Designed the UI with "message bubbles" and message attachments and connected it with messaging module.
- Ensured that all text in UI is accessibility supported while keeping the UI adapt to various text sizes.
- Developed other features like hidden admin settings in the app where the admin user can override some settings like environment selection or received chat message attachments for demo purposes.
Technologies: UIKit, iOS, Swift, Xcode, iOS Instruments, Accessibility, Video Streaming, Model View ViewModel (MVVM), Audio, Core Audio, Combine, iOS Animations, Figma, Object-oriented Programming (OOP), Agile Software Development, Git, Auto Layout, SnapKit, AVFoundation, UI Animation, Core Animation, gRPC
iOS/Swift Developer
2021 - 2022
Circular, LLC
- Developed a content planner module for the Pixelcut app, which enabled users to schedule their posts on Instagram.
- Developed a social login feature, which allowed users to login into the app via Google, Facebook, Apple, or classic email.
- Implemented various screens based on designs created in the Sketch app.
- Tracked and fixed bugs using Linear as a reporting tool.
- Engaged in code reviews, offering constructive input to fellow team members and enhancing the overall quality of the codebase.
Technologies: Swift, iOS, Firebase iOS SDK, Firebase, Xcode, iOS Instruments, UIKit, Core Animation, Google Login, Facebook Login, gRPC, Sketch, Figma, Object-oriented Programming (OOP), Agile Software Development, Cocoa Touch, Git, Model View ViewModel (MVVM), Auto Layout, Analytics, Core Graphics, AVFoundation, UI Animation, iOS Animations, Image Manipulation, Video Editing, Core Image, Facebook SDK, Video Streaming, TinyConstraints, Push Notifications, Mixpanel, Alamofire
iOS Engineer
2020 - 2021
Jumprope, Inc.
- Worked on lots of app features. Improved existing and added new features. Rewrote the video editor feature, where I implemented a custom collection view to add dynamics to the transitions of UI elements.
- Tracked and optimized the app for memory leaks using iOS Instruments.
- Led a project of migrating an app from React Native to native iOS. Rewrote React Native screens and functionalities in native iOS using the Swift programming language. Reduced clean-build time by two minutes.
- Led a subproject to create a desktop app where I used Mac Catalyst. Made sure no regressions were added to the existing mobile application while adjusting and implementing desktop-specific features in the same codebase.
- Engaged in code reviews, offering constructive input to fellow team members and enhancing the overall quality of the codebase.
Technologies: Swift, Xcode, iOS Instruments, AVFoundation, UIKit, RealmSwift, GraphQL, Object-oriented Programming (OOP), Agile Software Development, Cocoa Touch, Git, Firebase, Core Animation, Auto Layout, Analytics, Core Graphics, UI Animation, Sketch, iOS Animations, Image Manipulation, Video Editing, Core Image, Video Streaming, SnapKit, React Native, Push Notifications, Firebase iOS SDK, Alamofire
iOS Developer
2019 - 2019
2705433 Ontario Limited
- Built an app for organizing live social events in a team of two.
- Created various UI components like forms and messages and integrated them with the app.
- Made sure that all code was clean and had more straightforward maintenance.
Technologies: UIKit, TestFlight, RxSwift, Model View ViewModel (MVVM), GraphQL, REST, Git, Swift, Object-oriented Programming (OOP), Agile Software Development, Stripe, Geolocation, Payment APIs, Interface Builder, CocoaPods, Xcode, Cocoa Touch, iOS Instruments, Core Animation, Auto Layout, Core Graphics, UI Animation, iOS Animations, Location Services, Location Services and Maps, Push Notifications, Alamofire, Firebase
Senior iOS Architect
2019 - 2019
Zuvy, Inc.
- Collected requirements from the client and translated them into subtasks.
- Built a task and delivered a social iOS app from scratch based on requirements and UI designs.
- Helped the back-end developer in defining the API and integrating the app with the API.
- Configured beta tester distribution via TestFlight.
Technologies: UIKit, Maps, TestFlight, RxSwift, Model View ViewModel (MVVM), REST, Git, Swift, UI Animation, Object-oriented Programming (OOP), JSON, Agile Software Development, Stripe, Geolocation, Payment APIs, Interface Builder, Google Maps, CocoaPods, Xcode, Cocoa Touch, iOS Instruments, Core Animation, AFNetworking, Alamofire, Auto Layout, Core Graphics, Sketch, iOS Animations, Mobile Architecture, Location Services, Location Services and Maps, Push Notifications
iOS Developer
2019 - 2019
Countalytics
- Built a photo-capturing iOS app prototype that uses camera functionalities.
- Connected the app with a back-end API that other developers developed.
- Configured beta tester distribution via TestFlight.
Technologies: UIKit, TestFlight, RxSwift, Model View ViewModel (MVVM), REST, Git, Swift, Object-oriented Programming (OOP), JSON, Agile Software Development, Xcode, Cocoa Touch, Core Animation, AFNetworking, Alamofire, Auto Layout, Core Graphics, UI Animation, Sketch, iOS Animations, Image Manipulation, Core Image
iOS Developer
2018 - 2019
Selotsoft
- Built a hashtag messaging iOS app from scratch in a team of two iOS developers.
- Added new features and iterated through multiple UI/UX prototypes.
- Handled the UI/UX part of the project while also contributing to the API layer.
- Configured the beta tester distribution via TestFlight.
Technologies: UIKit, TestFlight, RxSwift, Model View ViewModel (MVVM), REST, Git, Swift, UI Animation, Object-oriented Programming (OOP), JSON, Agile Software Development, Stripe, Interface Builder, CocoaPods, Xcode, Cocoa Touch, iOS Instruments, Core Animation, AFNetworking, Alamofire, Auto Layout, Core Graphics, Sketch, iOS Animations, Image Manipulation, Core Image, Mobile Architecture, Location Services, Push Notifications, Mixpanel
iOS App Developer
2018 - 2018
Krazy Coupon Lady LLC
- Onboarded on an existing project in a short-term engagement to fix native push notifications implementation.
- Installed all needed tools for the React Native environment and push notifications test environment for sending test notifications.
- Debugged and fixed push notification bugs. Successfully merged fix into the codebase.
- Helped the team with deep linking campaign implementation and propagation of Segment events to Google Analytics.
- Fixed a couple of small UI bugs related to auto layout.
Technologies: iOS, Objective-C, Push Notifications, React Native, Segment, Google Analytics, Analytics
iOS Developer
2018 - 2018
Knoit
- Developed an iOS app prototype for a conversation hub, organizing conversations across channels like social and email into feeds.
- Built a UI component for the interactive creation of photo mosaics similar to the Instagram Layout app.
- Configured beta tester distribution via TestFlight.
Technologies: UIKit, TestFlight, RxSwift, Model View ViewModel (MVVM), REST, Git, Swift, UI Animation, Object-oriented Programming (OOP), JSON, Agile Software Development, Interface Builder, CocoaPods, Xcode, Cocoa Touch, iOS Instruments, Core Animation, AFNetworking, Alamofire, Auto Layout, Core Graphics, Sketch, iOS Animations, Image Manipulation, Core Image, Mobile Architecture, Google Login, Push Notifications
Senior iOS Developer
2016 - 2018
Sports Insights
- Built the iOS app Sports Insights from scratch in Swift using MVVM design pattern.
- Implemented all screens based on mockups and feedback from the client.
- Connected the application with the back-end API while communicating API compatibility and changes with the back-end developer. The app screencast video can be seen here: https://youtu.be/WHoyZPdfynk.
Technologies: iOS Instruments, Analytics, Crashlytics, StoreKit, Core Animation, Core Graphics, CocoaPods, Xcode, Swift, iOS, Object-oriented Programming (OOP), JSON, Agile Software Development, Payment APIs, Interface Builder, Cocoa Touch, Git, REST, UIKit, AFNetworking, Alamofire, Auto Layout, UI Animation, iOS Animations, Mobile Architecture, Segment, Facebook Login
iOS Developer
2016 - 2017
Airmee
- Created an iOS application prototype in Swift for the product MVP phase.
- Implemented a UI based on the provided screen mockups.
- Connected a client application with the back-end API.
Technologies: iOS Instruments, Maps, Core Animation, Core Graphics, CocoaPods, Xcode, Swift, iOS, Object-oriented Programming (OOP), JSON, Agile Software Development, Interface Builder, Cocoa Touch, Git, REST, UIKit, Google Maps, AFNetworking, Alamofire, Auto Layout, UI Animation, iOS Animations, Mobile Architecture, Location Services, Stripe
Senior iOS Developer
2016 - 2016
Docler USA, LLC
- Created a custom UICollectionView with the functionality to drag and drop cells between multiple collections. Feature screencast: https://youtu.be/PVP-aCQyuTE.
- Refactored host iOS application code using an outdated open source library for the drag-and-drop functionality.
- Integrated a new custom component into the host app.
Technologies: Swift, Objective-C, Xcode, iOS, Object-oriented Programming (OOP), Agile Software Development, Cocoa Touch, Git, UIKit, Core Animation, AFNetworking, Auto Layout, UI Animation, iOS Animations
iOS Developer
2016 - 2016
Piqua
- Created a Snapchat-like feature for photo/video capture (tap, long press) and editing. Feature screencast (temporary icons used during development): https://youtu.be/vEahlxVxT7Y.
- Translated design sketches for new features into app screens.
- Added different elements (text, finger drawing, sticker) as photo/video overlay and exported merged media (photo+overlay or video+overlay).
- Created a finger-drawing module to draw curves on the screen and ensure that lines look like a human had drawn them with a pencil.
- Ensured the separation of concerns while writing a new feature. Ensured that the new feature was easily pluggable into the existing app.
Technologies: iOS Instruments, Core Animation, Core Graphics, CocoaPods, Xcode, Objective-C, iOS, Object-oriented Programming (OOP), Agile Software Development, Cocoa Touch, Git, UIKit, UI Animation, iOS Animations, Image Manipulation, Video Editing, Core Image, AVFoundation
Mobile Software Developer and Engineer
2015 - 2016
Dream Factory
- Learned the Android platform and refreshed my Java skills.
- Created mobile SDKs for NextUser (http://www.nextuser.com), a user tracking and eCommerce personalization tool (iOS and Android SDKs).
- Gathered requirements, wrote tests, implemented features, and created test builds. Published an iOS SDK with CocoaPods.
- Learned the Swift programming language and its best practices.
- Created a module in the existing Objective-C app for data sync between the local database (Core Data) and remote database (Microsoft Azure) needed for offline app usage.
- Developed other iOS apps in Swift using the programming language.
Technologies: Android Studio, Java, Android, iOS Instruments, Xcode, Objective-C, Swift, iOS, Object-oriented Programming (OOP), JSON, Agile Software Development, Git, REST, AFNetworking, Alamofire, Analytics, Mobile Architecture, Location Services
iOS Software Developer and Engineer
2014 - 2015
Real Networks
- Developed RealTimes for iOS with the Zagreb and Seattle teams (eu.real.com/mobile/apps.html).
- Developed and designed lower-level features of the application, such as the network layer, auto-backup feature, sharing modules, location services module, video transcoding, etc., focusing on decoupling, modularity, and regular refactoring.
- Created the auto-backup module for RealTimes to automatically upload photos and videos. Both foreground and background uploads were supported.
- Created a location-based module to wake up the application at intervals on significant location changes so that the uploads can be continued while ensuring that the battery does not go empty because of the GPS tracking.
- Extracted the functionality of generating story-like videos from RealTimes into a separate SDK and helped integrate that SDK with other clients on-site in their offices.
- Used Apple tools for profiling and detecting application bottlenecks (iOS Instruments).
Technologies: iOS Instruments, Xcode, Objective-C, iOS, Object-oriented Programming (OOP), JSON, Agile Software Development, Interface Builder, Confluence, Cocoa Touch, REST, UIKit, Core Animation, Core Data, Alamofire, Core Graphics, AVFoundation, UI Animation, iOS Animations, Video Editing, Location Services, Video Streaming
iOS Software Developer and Engineer
2012 - 2014
Five Agency
- Worked with a remote team as part of the outsourced local team with a nine-hour time difference and gained valuable experience working with a client remotely.
- Learned Objective-C in-depth and best practices for building mobile apps.
- Used native iOS technologies and Agile programming methods.
- Implemented modules with defined APIs used in RealPlayer Cloud for iOS (later rebranded to RealTimes).
- Created modules for file upload and download that were used in the RealTimes iOS app for sharing photos and videos with other devices and remote servers.
- Collaborated with designers on best practices for developer-designer interactions.
Technologies: iOS Instruments, Xcode, Objective-C, iOS, Object-oriented Programming (OOP), JSON, Agile Software Development, Interface Builder, Confluence, Cocoa Touch, REST, UIKit, Core Animation, Core Data, Alamofire, Core Graphics, AVFoundation, UI Animation, iOS Animations, Video Editing, Video Streaming
Experience
Looks Good
https://youtu.be/RbqFsOITy0AIt's simple! When going somewhere and you want to look nice, your friends might not be around to help. Looks Good gives you access to fashionistas worldwide that want to instantly help you look your best.
I built the iOS app Looks Good from scratch in Objective-C. This side project challenged me to bring UI/UX into focus and make no compromises when implementing new features. Every UI transition and user action had to be polished and logical so that the app could feel "alive" while at the same time not going too crazy with animations so that they don't "take over" the purpose of user actions.
I built the iOS app Looks Good from scratch in Objective-C. This side project challenged me to bring UI/UX into focus and make no compromises when implementing new features. Every UI transition and user action had to be polished and logical so that the app could feel "alive" while at the same time not going too crazy with animations so that they don't "take over" the purpose of user actions.
Let Me In
http://five.agency/hackathon-project-letmeinAt an internal company hackathon at Fiveminutes, I developed a mobile application for unlocking office doors. The idea was that all of the people in an office could unlock the office doors when in the office's WiFi range. Used iOS/Android technologies and Arduino on the project. We were a team of three developers, and my job was to build mobile clients where I used Titanium SDK as a cross-platform solution. Mobile clients were communicating with Arduino over networks.
SmartHome App for Lights Manipulation
A SmartHome App that I've built for personal use.
I created an app with a custom UI and made an interactive UI with an apartment floor plan. Each room can be expanded/collapsed, each light can be toggled on/off, and if a particular light is RGB compatible, it can be changed in the app with a custom color picker. Additionally, all room lights can be toggled at once.
For UI, I mostly used CALayer because of the nature of the floor plan and room curvatures. I used Sketch to create a floor plan and exported it in SVG format, which I parsed inside the iOS app. After all room info was inside the iOS app in Bezier Path format, I could "give it a life" and make it interactive.
I used both IKEA Tradfri and Phillips Hue light bulbs but wanted to use Phillips bridge only, so I used a free Hue app that uses low-level ZigBee protocol and can add non-Phillips lights to the Phillips Hue bridge.
After all the lights were visible to the Phillips Hue bridge, I made a custom server that I ran locally on Raspberry Pi. This server publishes all the lights to HomeKit so that I can easily use HomeKit API inside the iOS app to scan all the devices on the network and connect them with custom UI and map all the lights to the actual light devices.
I created an app with a custom UI and made an interactive UI with an apartment floor plan. Each room can be expanded/collapsed, each light can be toggled on/off, and if a particular light is RGB compatible, it can be changed in the app with a custom color picker. Additionally, all room lights can be toggled at once.
For UI, I mostly used CALayer because of the nature of the floor plan and room curvatures. I used Sketch to create a floor plan and exported it in SVG format, which I parsed inside the iOS app. After all room info was inside the iOS app in Bezier Path format, I could "give it a life" and make it interactive.
I used both IKEA Tradfri and Phillips Hue light bulbs but wanted to use Phillips bridge only, so I used a free Hue app that uses low-level ZigBee protocol and can add non-Phillips lights to the Phillips Hue bridge.
After all the lights were visible to the Phillips Hue bridge, I made a custom server that I ran locally on Raspberry Pi. This server publishes all the lights to HomeKit so that I can easily use HomeKit API inside the iOS app to scan all the devices on the network and connect them with custom UI and map all the lights to the actual light devices.
Education
2009 - 2012
Master's Degree in Software Engineering and Information Systems
Faculty of Electrical Engineering and Computing - Zagreb, Croatia
2006 - 2009
Bachelor's Degree in Computer Science
Faculty of Electrical Engineering and Computing - Zagreb, Croatia
Skills
Libraries/APIs
Core Animation, SnapKit, TinyConstraints, Core Graphics, RxSwift, Alamofire, Google Maps, Stripe, CocoaPods, Facebook Pop, Facebook SDK, Firebase iOS SDK, Facebook Login, Sockets, SVGKit, Core Image, Core Audio
Tools
TestFlight, Trello, Xcode, Interface Builder, Figma, Slack, Crashlytics, iOS Instruments, Jira, Confluence, Auto Layout, Git, Appcelerator Titanium, Apple HomeKit, Google Analytics, Android Studio, Sketch
Languages
Swift, Objective-C, GraphQL, Java, JavaScript
Frameworks
UIKit, StoreKit, Cocoa Touch, AFNetworking, Core Data, gRPC, Combine, RealmSwift, SwiftUI, React Native
Paradigms
Model View ViewModel (MVVM), Agile Software Development, REST, Object-oriented Programming (OOP)
Platforms
iOS, Amazon Web Services (AWS), Firebase, Mixpanel, Android, Raspberry Pi, MacOS
Storage
JSON, Amazon S3 (AWS S3)
Other
AVFoundation, UI Animation, iOS Animations, Mobile Architecture, Analytics, Maps, Google Login, Geolocation, Payment APIs, SVG, Image Manipulation, Video Editing, Location Services, Location Services and Maps, Video Streaming, Accessibility, Audio, Push Notifications, Segment
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