Sebastian Krajna
From: Poland
Location: Cekcyn
On Useme since 5 July 2023
About me
I build Flutter apps for iOS and Android — from architecture to App Store and Google Play.
Currently a Software Engineer at Tealium: mobile SDKs (Prism) for iOS, Android, Flutter, and React Native, including Firebase and Braze integrations.
Freelance, separately: • Venax — transport orders and rewards (Android + iOS) • Bliżej — community platform: admin, mobile app, roles, realtime • GuideAway — paid tour routes, offline maps, Stripe • Native plugins and SDK wrappers (Swift / Kotlin)
Stack: Flutter, Dart, Swift, Kotlin, React Native, Firebase, Supabase.
I take on new apps, features, and native bridges. Short written scope first. You get working builds.
Categories
Portfolio
Samodzielnie opracowanie i wdrożenie aplikacji mobilnej Venax na Android i iOS, dostępnej w Google Play oraz Apple Store. Projektowanie i wdrażanie intuicyjnego interfejsu UI/UX. Integracja z Firebase. Wdrożenie funkcji wysyłania wiadomości e-mai
Working in a team of 2-4 people on the SoloCoach application for personal trainers. Developing a calendar functionality for managing meetings. Creating a diet and meal screen with the option of filtering. Communication with REST API.
A simple diagnostic tool communicating via Bluetooth with OBD. Implemented REST API communication for user authentication and license verification.
Developing OinkSave, a group budgeting app with multi-category and wallet support.
Developed MaxiEcu 3.0 (Windows, Android) – a diagnostic tool communicating via Bluetooth with OBD. Implemented REST API communication for user authentication and license verification. Employed Isolates for background database downloads within the a