Jonatan Kats · Mobile Developer · 14 Years

15+ production apps shipped across fintech, media, gaming, and enterprise security.

15+
Apps Shipped
14
Years Experience
3
Platforms
6
Industries
Full-stack mobile engineer specializing in native iOS (Swift/SwiftUI/UIKit), Android (Kotlin/Compose), and cross-platform Flutter. From consumer apps with millions of users to enterprise security agents — if it runs on a phone, I've built it.
What I Bring
Native depth across platforms
14 years of Swift/Objective-C and production Kotlin/Compose. Not just "works on both" — pixel-perfect native UX on each platform. Built apps with CarPlay, Bluetooth LE, ARKit/SceneKit 3D rendering, Core Data, and background processing pipelines.
Architecture that scales
MVVM, VIPER, Coordinator pattern, MVC with custom base classes. Built modular CocoaPod libraries shared across multiple app targets. Designed multi-region build systems with 9+ regional targets from a single codebase.
Complex system integration
Real-time communication (Socket.IO, Twilio VoIP), payment gateways, blockchain/Web3 wallets, Bluetooth LE device detection, push notification pipelines with service extensions, and deep linking across multiple URL schemes.
Cross-platform velocity
Flutter/Dart for shared logic with native look and feel. HTML-based solutions when appropriate. Ship to both stores from a single codebase while maintaining platform-specific UX expectations.
AI-assisted development
Integrated AI coding tools (Claude, OpenCode, Deepseek) into daily workflow for code review, refactoring, and problem-solving. Faster iteration, cleaner code — not replacing engineering judgment, augmenting it.
SKILLS & TOOLS
Swift SwiftUI UIKit Objective-C Kotlin Jetpack Compose Flutter/Dart ARKit/SceneKit Core Data Realm Firebase Alamofire RxSwift CocoaPods Carthage REST APIs GraphQL Socket.IO Bluetooth LE Web3/Crypto CarPlay MVVM VIPER Coordinator Git/GitHub Fastlane SwiftLint

Jonatan Kats

Mobile Developer · iOS · Android · Flutter · 14 Years Experience
Bit Apps
Jul 2016 – Present
Senior iOS & Android Engineer
Led development of 11 production mobile applications across iOS and Android, spanning fintech, media, gaming, enterprise security, retail, and nonprofit sectors. Owned architecture decisions, built shared libraries, and delivered pixel-perfect implementations from Figma specs.
  • e-book & audiobook platform — Architected a full-featured reading app with CarPlay audiobook playback, offline-first Realm persistence, inline text translation via SwiftUI-hosted views, iOS home screen widgets, and a custom notification service extension. Built with MVC + ProcedureKit for complex async operation management. Shipped to the App Store serving a large user base.
  • Gambling platform — Engineered a multi-region iOS app with 9+ regional build targets (US states, Australia, Mexico, global), each with distinct bundle IDs, Firebase configs, and notification service extensions. Built a shared CocoaPod core library with Alamofire, Firebase Crashlytics/Messaging, Facebook SDK, and AppsFlyer attribution. Designed iPad-first UI with separate XIB files per device class.
  • Modular core library (CocoaPod/SPM) — Created a reusable iOS library distributed via private CocoaPods spec repository, encapsulating networking, analytics, logging, and common UI components. Used as a foundational dependency across multiple app targets, reducing code duplication by ~60%.
  • 3D volumetric video platform — Built an iOS app for recording, editing, and playing back volumetric 3D video using SceneKit rendering and a proprietary native codec. Implemented MVVM + Coordinator pattern with 11 coordinators, CoreData persistence, NFT wallet integration via WalletConnect, and Microsoft enterprise authentication. Two separate app targets with shared modules.
  • Photography competition platform — Delivered a social gaming app with real-time Socket.IO voting, team battles with live chat, Tinder-style photo swiping (Koloda), rewarded video ads, in-app purchases, and an achievement/badge system. Integrated 5 login providers (Email, Facebook, Twitter, Apple, Google). 334+ Swift files with 50+ ViewModels using a custom Bindable reactive pattern. Integrated Braze, Mixpanel, AppsFlyer, and Google Tag Manager for engagement analytics.
  • Crypto/DeFi browser — Built a Web3 browser app with VIPER architecture, custom JavaScript injection for dApp interaction, Fortmatic wallet authentication, and AR module. Firebase Analytics + Crashlytics for production monitoring.
  • leading parking & fueling payment app — Maintained and extended a high-traffic production app with Bluetooth LE automatic parking detection, server-driven dynamic UI (XML/plist-based menu system), Google Maps + Waze integration, QR code parking lot payments, fueling workflow with coupon management, and a parking patrol detection system. Mixed ObjC/Swift codebase with MVVM for new features, RxSwift for reactive location services, and multi-language support.
  • Enterprise cybersecurity agent — Developed an endpoint protection iOS agent with device security assessment, policy management, file scanning, batched telemetry upload, Twilio VoIP calling, and QR code-based device enrollment. RxSwift reactive architecture with background fetch and remote notification monitoring. Multi-locale support.
  • Charitable donations platform — Built a donations app with credit card payment processing, card management, fund browsing, news feed, and in-app chat support. Alamofire + ObjectMapper networking layer with Google Sign-In authentication.
  • News/media application — Developed a real-time news app with article streaming, push notifications, offline reading, and breaking news alerts. Core Data persistence with background fetch for seamless offline experience.
Swift Objective-C Kotlin SwiftUI UIKit SceneKit/ARKit Core Data Realm CocoaPods Carthage Alamofire RxSwift Socket.IO Firebase Bluetooth LE CarPlay Web3/WalletConnect REST APIs MVVM/MVI VIPER Coordinator Fastlane
sport.com
Nov 2015 – Jul 2016
iOS Developer
Developed a fitness-focused social sharing application for iOS, enabling users to track workouts, share photo/video progress, and engage with a fitness community. Implemented activity tracking with Core Location, social feed with push notifications, and real-time content sharing.
Objective-C Swift UIKit REST APIs Core Location Social Frameworks Push Notifications
Gini-Apps
Jan 2013 – Nov 2015
iOS Developer
Built and maintained multiple iOS applications in news/media and fintech domains during the early Swift era. One of the first developers to adopt Swift during its initial release, leading migration of legacy Objective-C components.
  • Major news application — Developed a real-time news app delivering articles, video content, and breaking news alerts. Implemented background fetch for seamless offline reading and push notification pipeline for instant alerts.
  • Parking payment application — Built location-based parking payment features with MapKit integration, GPS-based zone detection, and payment processing. Core Data for offline transaction queuing.
  • Early Swift adoption — Migrated components from Objective-C to Swift during the language's first year of release, establishing patterns and best practices for the team. Built new features in Swift while maintaining backward compatibility with ObjC codebase.
Objective-C Swift (early adoption) UIKit Core Data MapKit REST APIs Push Notifications Background Fetch
Open Source Projects
BottomShelfer — iOS
github.com/jonikay89/BottomShelfer-ios
Customizable bottom sheet component for iOS, built with Swift and UIKit. Supports dynamic sizing, gesture-driven dismissal, and smooth animations.
BottomShelfer — Android
github.com/jonikay89/BottomShelfer-android
Customizable bottom sheet component for Android, built with Kotlin and Jetpack Compose. Supports flexible layouts, swipe gestures, and Material Design integration.
BottomShelfer — Flutter
github.com/jonikay89/BottomShelfer_flutter
Cross-platform bottom sheet component built with Flutter and Dart. Delivers native-like bottom sheets on both iOS and Android from a single codebase with gesture-driven dismissal and smooth animations.