Ян

Yan Kohut
Mobile Developer · Flutter / Android / iOS6 years experience
[open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section) · @yan_and_free · Cherkasy, Ukraine

SUMMARY

Mobile Engineer with 6+ years building cross-platform iOS and Android applications. Specialised in Flutter with deep native integration experience in Kotlin and Swift. Delivered production apps from greenfield to store across agencies and product companies — including tech lead responsibilities on a 30-person e-commerce team. Experienced in CI/CD pipeline setup (GitHub Actions, Fastlane), unit testing, Java-to-Kotlin migration, and AWS cloud integration (Amplify, Cognito, SNS).
SKILLS

Languages: Dart, Kotlin, Java, Swift
Frameworks: Flutter, Android SDK, Jetpack Compose
Architecture: MVVM, MVP, BLoC, Riverpod, Feature-First
Tools: Git, Firebase, REST API, GraphQL, SQL, Figma, GitHub Actions, Fastlane, AWS SDK (Android / Kotlin), Unit Testing, JUnit
English: C1

WORK EXPERIENCE

Smoke Free · Mobile DeveloperSep 2025 – May 2026
Supporting developer on a quit-smoking app with 8M+ downloads and 185K five-star ratings — the highest-rated app of its kind. Contributed to both Android (Kotlin, Koin, Coroutines) and iOS (Swift, Objective-C) codebases across two parallel teams.
Responsibilities:
• Developed and integrated new features in collaboration with the University of East Anglia, including user surveys and an AI chat assistant.
• Maintained and optimized the existing codebase across Android and iOS platforms.
• Led Java-to-Kotlin migration across ~20% of the Android codebase, porting complete features rather than individual files.
• Set up mobile CI/CD pipeline from scratch using GitHub Actions (build, test, deploy).
Technical solutions:
• Integrated an AI chat feature by connecting Flutter UI to a backend-provided service via Method Channels.
• Migrated existing native functionality to Flutter via Method Channels, ensuring functional parity across platforms.
• Wrote unit tests covering business logic and migrated modules, including Kotlin code migrated from Java.
• Configured Fastlane lanes for automated build and deployment as part of the CI/CD pipeline.
• Integrated Firebase across both Android and iOS codebases.
Technical stack:
Flutter, Kotlin (Koin, Coroutines), Swift, Objective-C, Firebase, Method Channels, JUnit, GitHub Actions, Fastlane
Krootl · Mobile DeveloperApr 2024 – Aug 2025
AstrolabiumSep 2024 – Jul 2025
Stack: Flutter (Riverpod, go_router), Kotlin, Swift, Method Channels, Google Pay, Apple Pay, REST API, Fastlane
An e-commerce app for a Ukrainian publisher known for the Ukrainian Lord of the Rings translation, featuring a custom audiobook player and book reader.
Responsibilities:
• Developed and maintained cross-platform Flutter application for iOS and Android.
• Wrote native audiobook player and book reader implementations in both Kotlin and Swift, integrated into Flutter via Method Channels.
• Integrated Google Pay and Apple Pay payment flows.
Technical solutions:
• Designed and implemented a feature-first architecture for scalability and team autonomy.
• Built custom native audio and reading engines in Kotlin and Swift, bridged to Flutter via Method Channels.
• Integrated payment processing via Google Pay and Apple Pay.

NestEggApr 2025 – Aug 2025
A corporate fitness competition platform integrating Apple Health, Google Fit, and Garmin for activity tracking across teams.
Responsibilities:
• Developed frontend-focused features across Flutter mobile, Flutter Web admin panel, and Node.js backend within a team of 5.
• Built admin panel modules for race/competition result display and team management (add, edit, delete, manage members).
• Integrated Garmin Health API for activity data synchronization.
Technical solutions:
• Integrated Garmin Health API, pulling the full range of activity data including steps, heart rate, and workout history.
• Developed team and competition management modules in the Flutter Web admin panel.
• Contributed to Node.js backend alongside two other fullstack developers.
Technical stack:
Flutter (Riverpod, Firebase), Flutter Web, Node.js, Garmin Health API, Apple Health, Google Fit, Stripe, Fastlane
CustomItem · Mobile DeveloperJan 2024 – Sep 2024
CustomItem AppJan 2024 – Sep 2024
Stack: Flutter (BLoC, Flutter Navigator), GraphQL (graphql_flutter), Kotlin / Swift AWS SDK (Amplify, Cognito, SNS), Method Channels, iOS & Android
A cross-platform mobile e-commerce application for iOS and Android, developed within a team of 30 people.
Responsibilities:
• Led a sub-team of 3 developers: conducted code reviews, mentored junior developers, and coordinated with backend and design teams.
• Developed and maintained frontend features using Flutter with BLoC state management.
• Collaborated on architecture decisions and feature delivery across the full mobile stack.
Technical solutions:
• Designed and implemented a feature-first architecture to improve scalability and team autonomy.
• Integrated a custom OpenGL-based 3D engine into the Flutter application using Method Channels.
• Implemented GraphQL data layer using graphql_flutter with AWS Amplify and Cognito for authentication.
• Built a custom navigation system on top of Flutter Navigator, replacing third-party routing packages.
• Developed a full hybrid design system combining Material and Cupertino principles with a custom widget library, ensuring consistent UI across iOS and Android.
• Set up push notification delivery pipeline via AWS SNS.

CookieDev · Mobile DeveloperOct 2020 – Dec 2023
AuraSep 2023 – Dec 2023
Stack: Flutter, Riverpod, REST API (Dio), RevenueCat
StackOverflow-style knowledge-sharing platform for medical professionals. Built complex responsive UI with advanced animations.
CofioJan 2023 – Jun 2023
Stack: Flutter, Riverpod, Google Maps API, RevenueCat, offline-first
Travel journal app for iOS and Android with offline-first architecture, expense tracking, and an interactive world map.
LABA7 ScaleAug 2022 – Dec 2022
Stack: Flutter, BLoC, Bluetooth / BLE, custom Canvas UI
Car calibration app for mechanics. Reverse-engineered BLE device protocol, decrypted sensor data, and built a custom canvas visualization of center-of-mass calculations.
Shepherd GuardDec 2021 – Feb 2022
Stack: Android, Kotlin, MVVM, NFC, Retrofit, Hilt
Security guard management app (tracker + check-in + RFID programming). Built a custom NFC read/write library still in active use by the client.
LifeCassetteJul 2021 – Oct 2021
Stack: Android, Kotlin, MVVM, RxJava, Firebase Firestore, Hilt
Social journaling app with complex custom UI and real-time backend.
Chuck the Farmer / Nutrihorse (minor)Oct 2020 – Jun 2021
Stack: Android, MVP, RxJava, Lottie, REST API
Two early-career Android apps.

EDUCATION

Bachelor of Computer Science
Bohdan Khmelnytsky National University of Cherkasy