Оскар

OSKAR SAIENKO
FRONTEND DEVELOPER

CONTACT INTRODUCTION
Frontend Developer with 2+ years of experience building and maintaining
[open contact info](look above in the "contact info" section)
production-grade mobile and web applications (React Native, Next.js).
Lviv, Ukraine Experienced in monorepo architectures, SDK migrations, payment
integrations, and improving app stability in multi-app ecosystems.
[open contact info](look above in the "contact info" section)
saienko-64a652254/
WORK EXPERIENCE
https://github.com/osichan
Frontend Developer Jan 2026 - Now
https://t.me/osichan Admiral Studios, Remote
IImplemented financial integrations (Plaid, Stripe) and transaction processing logic.
Ensured data consistency across financial flows and state management.
SKILLS Optimized performance of activity feeds and large transaction lists.
Implemented connections to plaid and stripe.
Frontend: React Native, React, Optimized data handling and sorting logic for transaction/activity lists.
Next.js Improved UI/UX handling in React Native components, including text truncation,
layout fixes, and state-driven rendering.
State: Redux Toolkit, Zustand
Backend/Services: Firebase, AWS, Frontend Developer Jun 2025 - Dec 2025
Linkup st, Remote
GCP
Worked on a large-scale food-tech ecosystem including a web client, two mobile
Payments: Stripe, Revolut, Plaid apps (Customer & Chef), and two shared component repositories (design system +
Tools: Expo, Zod, CI/CD UI library).
Maintained and extended complex multi-app architecture.
(Codemagic, GitHub Actions) Monorepo work: 2 independent mobile apps + 2 shared component libraries.
Mobile: Android SDK, Gradle, Kotlin, Involved in payment integrations: Stripe & Revolut (confirmation flows,
troubleshooting).
Xcode Full project modernization: RN 0.7x, Gradle 8.x, Android SDK 35, Kotlin versions,
autolinking fixes.
Resolved complex architecture-related issues (navigation, state consistency,
LANGUAGES race conditions, native integrations), improving overall app stability.
Improved performance and stability across apps.
English (B1+) CI/CD involvement: fixed build failures, environment inconsistencies,
dependency conflicts.
Ukrainian (C2)
Frontend Developer Dec 2024 - Jun 2025
Russian (C2)
Appexoft, Office
Developed mobile and web applications using React Native, Expo, Next.js, Redux
Toolkit, Firebase, and Zod.
EDUCATION Implemented camera features, voice input, and real-time geolocation.
Built responsive UI and improved cross-platform performance.
Lviv Polytechnic Deployed apps to App Store and Google Play from scratch, ensuring compliance
with platform guidelines
Relevant courses:
Teamwork and Presentation skills
Algorithmization and programming React Native Developer Apr 2024 - Aug 2024
Algorithms and data structures Freelance, Remote
Web development Developed advanced PDF generation, editing, and viewing functionality.
Relational databases Implemented AWS-based secure authentication.
Operating systems Collaborated with a Ukrainian-American distributed engineering team.

React Native Developer Jul 2023 - Jun 2024
Startup Wombase, Lviv
Built a React Native application from scratch to production APK.
Participated fully in design, development, deployment, troubleshooting.
Resolved runtime issues to ensure stable operation across devices.