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Roman Onishchenko

@onishchenko-roman

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Senior Software Engineer with 12+ years of experience in software development.

Poland

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Experienced in owning product features end-to-end, from requirements analysis and technical design to frontend and backend implementation, API development, testing, and production delivery. Contributed to software architecture decisions across both frontend and backend systems.

Strong background in frontend architecture, system design, and full-stack development, with hands-on experience modernizing large codebases, improving application reliability, and building maintainable production systems.

Actively expanding expertise in AI engineering through hands-on projects involving LLMs, RAG, AI agents, multi-step workflows, and AI integrations. Experienced in AI-assisted software development using Claude Code.

Always interested in learning new technologies and improving engineering workflows.

Experience

Work history, roles, and key accomplishments

Senior Full-Stack Engineer

N-iX

Aug 2021 - Apr 2026 (4 years 8 months)

Owned end-to-end delivery of product features, from requirements analysis and technical design through frontend and backend implementation, testing, release coordination, and production validation. Drove technical and architectural decisions across frontend and backend, defining API patterns, data flows, error-handling strategies, and scalable solutions for business-critical functionality.

React TypeScript Redux toolkit React Query NodeJS AWS Docker CI CD GitHub Actions Git System Design Claude Code

Senior Frontend Engineer

Software Development Hub

Sep 2020 - Aug 2021 (11 months)

Led frontend development for a CMS platform, coordinating feature delivery and technical decisions. Designed reusable UI components and refactored legacy flows to improve maintainability.

React TypeScript UI Components Refactoring Collaboration

Frontend Developer

Roll'n'Code

Nov 2019 - Oct 2020 (11 months)

Maintained and improved a web-based reading platform, focusing on usability and performance. Built frontend features using React and TypeScript and added unit test coverage.

React TypeScript Unit Testing Performance Optimization

Full-Stack Developer

RaiseNow

Jul 2018 - Oct 2019 (1 year 3 months)

Contributed to the development of a Switzerland fundraising platform, supporting donation flows and user interactions. Improved stability of a legacy React/TypeScript codebase and implemented UI enhancements.

React TypeScript Python UI Development

Full-Stack Developer

Eltima Software

Jan 2013 - Jul 2018 (5 years 6 months)

Maintained company websites and product landing pages, building frontend with JavaScript and jQuery. Contributed to backend development using PHP and MySQL.

JavaScript jQuery PHP MySQL Refactoring

Education

Degrees, certifications, and relevant coursework

Woolf University

Master's Degree, Computer Science

2023 - 2026

Grade: 4

Activities and societies: Pursuing a Master's Degree in Computer Science with a focus on Software Engineering.

This Master of Science in Computer Science worth 90 ECTS credits, represents 18 months (2250 hours) of study. The Malta Further and Higher Education Authority (MFHEA) deems this degree to be at the EQF7 of the Malta Qualifications Framework and the European Qualifications Framework for Lifelong Learning. Woolf is a licensed Higher Education Institution (2019-015).