Description

Senior Full-Stack Engineer with 15 years building high-performance web and mobile applications across e-commerce, healthtech, fintech, and adtech. Core stack: React (8+ yrs), TypeScript, Node.js (6+ yrs), Python (FastAPI — production project shipped), and React Native (Expo).

I actively integrate AI development tools (Claude Code and similar) into my workflow, gaining measurable speed and flexibility across prototyping, debugging, and delivery.

Proven at both team delivery and solo end-to-end execution — I've driven architecture decisions on monorepos and federated GraphQL, and independently shipped production services, mobile apps, and side projects. Infrastructure experience spans Docker, Kubernetes (production), AWS, GCP, Terraform, and cost-effective fly.io + SQLite + Litestream setups.

Learning Python, preparing for AWS Solutions Architect certification. Former lecturer at Kyiv Polytechnic (3 course streams, 200+ students).

Languages

English
Fluent
Ukrainian
Native or bilingual
Russian
Native or bilingual
German
Basic
Portuguese
Basic

Workplace preferences

Can work on-site

Lisbon (up to 50km)

PelagoApps
Senior FullStack Engineer
HEALTH AND WELLNESS
August 2025 - October 2025 (2 months)
Lisbon, Portugal
• • Developed features for AI HealthTech mobile applications using React Native, TypeScript, and Firebase/Firestore backend.
• • Implemented analytics infrastructure (Firebase Analytics, BigQuery) and third-party integrations (OneSignal, Adjust).
• • Integrated LangChain/LangSmith for AI-powered health recommendations, working on prompt engineering and model interaction flows.
React Native Typescript Langchain Firebase BigQuery
Aignostics GmbH
Senior Fullstack Engineer
November 2023 - November 2024 (1 year)
Berlin, Germany
• • Built and optimized UI components handling complex data visualization for pathology workflows, supporting datasets with 2,000+ slides and enabling real-time interactions for clinical users.
• • Refactored the entire application routing system, resolving over 10 persistent navigation and breadcrumb issues, which led to a 20% drop in user-reported bugs across two release cycles.
• • Designed and implemented a robust integration testing approach that simulates real user navigation via the router. This caught 10+ critical bugs before they hit the main branch, preventing regressions and improving release confidence.
• • Built a comprehensive test suite (React Testing Library, Cypress) covering 20+ routing paths and key pages, significantly reducing QA bottlenecks and increasing automated test coverage by 35%.
• • Architected performance optimizations for data-heavy onboarding module, scaling from 100 to 2,000+ slides while maintaining smooth UX, improving load times by 60% and enabling support for enterprise clients.
• • Fixed over 50 UI and API bugs ofvarying criticality — both proactively and reactively — improving product polish and easing developer handover between sprints.
• • Unified and modernized the TypeScript build setup across the monorepo. This led to a 40% faster CI job runtime and improved DX for all team members working in the shared codebase.
• • Led architectural discussions and design reviews, serving as technical lead for frontend decisions on routing, testing, and performance optimization.
Typescript React.js Node.js Python Google cloud
N-iX -forBWT
Senior FullStack Engineer
November 2022 - November 2023 (1 year)
Kyiv, Ukraine, 02000
• • Refactored component library for better performance and maintainability.
• • Led the transition to Federated GraphQL across microservices, reducing average query response time by 40% and improving data modularity for 3 frontend subteams.
• • Unified architecture across owned apps; introduced shared patterns and documentation.
• • Enhanced CI/CD pipeline with pre-commit hooks, automated linting, and unit tests, reducing main branch issues by 25%.
Node.js React Native