Денис

Denys Filonenko
Senior Flutter Engineer · Kyiv, Ukraine
[відкрити контакти](див. вище в блоці «контактна інформація») · [відкрити контакти](див. вище в блоці «контактна інформація») · LinkedIn

Summary
Flutter engineer with 6+ years in software development, including 5 years building production
Flutter apps for Android and iOS. Experienced in owning mobile apps end to end as a sole
developer, from architecture to store releases.
Strong at decomposing complex legacy code, designing client architecture, integrating backends,
profiling performance and tracking down hard issues to their root cause, from native build
tooling conflicts to device-specific bugs.
I enjoy taking ownership: making technical decisions, proposing and driving improvements, and
seeing them through to production. I work closely with backend, QA and product, and
communicate trade-offs openly.

Experience
CASAFARI — Mobile Application Developer
Jan 2024 – Nov 2026 · Remote (Lisbon, Portugal)
CASAFARI AI is a real-estate intelligence app that aggregates property data from all major portals
in many European countries and the UAE into one platform; 20,000+ downloads on the App Store
and Google Play.
● Sole Flutter developer of the app: owned features, architecture, integrations and releases.
● Re-architected the app: migrated state management from MobX to Riverpod and
introduced Clean Architecture, MVVM and feature-based modules with explicit dependency
injection through providers.
● Built map-based property search on Google Maps: clusters, several marker types,
draw-to-search, viewport-driven filtering and camera control behind a library-agnostic map
abstraction.
● Delivered product features: OAuth sign-in, advanced search filters, saved-search alerts with
push notifications, deep links and shareable property smart links, property valuation
reports, favorites and QR login to the web platform.
● Integrated REST APIs (Dio, cookie-based sessions, error handling), Firebase, PostHog and
Google reCAPTCHA with backend verification.
● Improved UI and raster thread performance on Android and iOS, verified by profiling frame
times and jank before and after changes.
● Owned app releases to the App Store and Google Play through CI/CD pipelines (Jenkins,
Fastlane, GitHub Actions).
● Kept the build healthy: Flutter and dependency upgrades, Android Gradle Plugin, NDK and

SDK migrations, CocoaPods and Swift Package Manager conflicts.

Qooco — Flutter Developer
Nov 2021 – Jan 2024
Qooco Talk is an English and Chinese learning app; 5,000+ downloads on Google Play.
● Migrated modules of the legacy native app to Flutter.
● Built new features and interactive learning lessons using BLoC and Cubit.
● Developed interactive mini-games with the Flame game engine and Spine animations.
● Took part in code review, app architecture and business logic design.

Taxi UA — Cross-Platform App Developer
Nov 2020 – Nov 2021
Taxi UA is an app for taxi drivers in Ukraine with direct fuel discounts at partner filling stations
and related driver services; 100,000+ downloads on Google Play.
● Sole developer, fully responsible for the app from development to Google Play release; built
it with JavaScript and Apache Cordova.
● Implemented custom native Cordova modules and Firebase integration.
● Worked with IT teams of filling-station chains and other partners on service integrations.

Earlier experience
● SoftLogic Taxi — Frontend Developer, Jun 2020 – Nov 2020: web modules integrated into
taxi service mobile apps.

Skills
● Core: Dart, Flutter (Android, iOS)
● Architecture: Clean Architecture, SOLID, MVVM, feature-based modularization,
dependency injection
● State management: Riverpod, BLoC / Cubit, Provider, MobX
● Networking: REST APIs, Dio, http, cookie and session-based auth, error handling
● Maps: Google Maps, GPS geolocation, GeoJSON, clustering, camera control, drawing on the
map
● Storage & caching: Hive, sqflite / Drift, shared_preferences, flutter_secure_storage
● Services: Firebase, PostHog, Google reCAPTCHA
● Delivery: Git, Jenkins, Fastlane, GitHub Actions, App Store and Google Play releases
● Testing: unit, widget and integration tests (flutter_test, mocktail), testable architecture
through dependency injection
● Web: JavaScript, TypeScript, Vue.js, React, Redux, HTML/CSS
● Languages: English (Upper-Intermediate, B2), Ukrainian (native)