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I’m Illia Hulenko, a full stack developer with 5+ years of experience building scalable web applications and improving performance and reliability end to end. I’ve delivered React-based platforms used by 50,000+ external users and 12,000+ employees, working with TypeScript, Node.js, Express, and PostgreSQL while strengthening UI performance, API efficiency, and code quality through testing. I enjoy engineering collaborative solutions with measurable impact—like reducing server load times by 50% using Redux optimization and code splitting, and lowering QA defects by writing Jest test coverage for critical React components. I’m also deepening my high-performance backend focus by building production applications with Rust, Axum, Tokio, and Dioxus, while keeping a strong foundation in Agile/Scrum workflows and developer tooling.…I’m Illia Hulenko, a full stack developer with 5+ years of experience building scalable web applications and improving performance and reliability end to end. I’ve delivered React-based platforms used by 50,000+ external users and 12,000+ employees, working with TypeScript, Node.js, Express, and PostgreSQL while strengthening UI performance, API efficiency, and code quality through testing. I enjoy engineering collaborative solutions with measurable impact—like reducing server load times by 50% using Redux optimization and code splitting, and lowering QA defects by writing Jest test coverage for critical React components. I’m also deepening my high-performance backend focus by building production applications with Rust, Axum, Tokio, and Dioxus, while keeping a strong foundation in Agile/Scrum workflows and developer tooling.

Illia Hulenko

Full Stack Developer, Back-End Developer, Front-End Developer, +3

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I’m Illia Hulenko, a full stack developer with 5+ years of experience building scalable web applications and improving performance and reliability end to end. I’ve delivered React-based platforms used by 50,000+ external users and 12,000+ employees, working with TypeScript, Node.js, Express, and PostgreSQL while strengthening UI performance, API efficiency, and code quality through testing. I enjoy engineering collaborative solutions with measurable impact—like reducing server load times by 50% using Redux optimization and code splitting, and lowering QA defects by writing Jest test coverage for critical React components. I’m also deepening my high-performance backend focus by building production applications with Rust, Axum, Tokio, and Dioxus, while keeping a strong foundation in Agile/Scrum workflows and developer tooling.…I’m Illia Hulenko, a full stack developer with 5+ years of experience building scalable web applications and improving performance and reliability end to end. I’ve delivered React-based platforms used by 50,000+ external users and 12,000+ employees, working with TypeScript, Node.js, Express, and PostgreSQL while strengthening UI performance, API efficiency, and code quality through testing. I enjoy engineering collaborative solutions with measurable impact—like reducing server load times by 50% using Redux optimization and code splitting, and lowering QA defects by writing Jest test coverage for critical React components. I’m also deepening my high-performance backend focus by building production applications with Rust, Axum, Tokio, and Dioxus, while keeping a strong foundation in Agile/Scrum workflows and developer tooling.

Available to hire

I’m Illia Hulenko, a full stack developer with 5+ years of experience building scalable web applications and improving performance and reliability end to end. I’ve delivered React-based platforms used by 50,000+ external users and 12,000+ employees, working with TypeScript, Node.js, Express, and PostgreSQL while strengthening UI performance, API efficiency, and code quality through testing.

I enjoy engineering collaborative solutions with measurable impact—like reducing server load times by 50% using Redux optimization and code splitting, and lowering QA defects by writing Jest test coverage for critical React components. I’m also deepening my high-performance backend focus by building production applications with Rust, Axum, Tokio, and Dioxus, while keeping a strong foundation in Agile/Scrum workflows and developer tooling.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Intermediate

Language

Ukrainian

Fluent

English

Advanced

Spanish; Castilian

Advanced

Work Experience

Full Stack Developer at Ingetum Norte

April 1, 2025 - October 1, 2025

Built and optimized a React-based web application used in the energy supply sector by 50,000+ users. Reduced server load times by 50% by refactoring Redux store interactions and creating custom hooks to eliminate duplicate requests. Improved page load speed by cutting memory usage and applying code splitting, lazy loading, memoization, and re-render pruning with React hooks. Reduced QA defects by authoring comprehensive Jest unit tests for core React components. Architected Node.js and Express.js REST endpoints to enable synchronous SAP data exchange and confirm reduced API latency. Lowered CI/CD integration errors by 40% by standardizing pull request documentation and automating Jenkins deployments across dev and QA branches.

Full Stack Developer (React-based web application) at Inetum Norte

April 1, 2025 - October 1, 2025

Built and optimized a React-based web application serving 50,000+ users in the energy supply sector. Reduced server load times by 50% through Redux store interaction refactoring and custom hooks to eliminate duplicate requests, validated via SAP integration metrics. Improved page load speed and lowered memory consumption by deploying code splitting, lazy loading, memoization, and re-render pruning using React patterns such as useCallback and useMemo. Reduced QA defects by writing comprehensive Jest unit tests for core React components and catching logic issues pre-deployment. Designed Node.js + Express REST endpoints to support synchronous SAP data exchange and reduce API latency by replacing legacy database queries. Lowered CI/CD integration errors by 40% by standardizing pull request documentation and automating Jenkins deployments across dev and QA branches.

Full-Stack Developer at Softtek

January 1, 2022 - July 1, 2024

Developed a MERN stack application supporting 12,000 employees. Shortened feature development cycles by engineering reusable custom hooks and HO Cs while stabilizing global state management with Redux. Improved application stability by reducing runtime crashes through implementation of the Observer pattern and robust Redux state management. Boosted platform reliability by maintaining Jest test suites for core React components to catch regressions early. Increased data retrieval efficiency by building optimized RESTful endpoints and middleware using Node.js and Express.js. Decreased database bottlenecks by designing and optimizing complex relational queries in MySQL.

Full-Stack Developer (MERN) at Softtek

January 1, 2022 - July 1, 2024

Developed a MERN stack application used by 12,000 employees. Shortened feature development cycles by engineering reusable custom hooks and HOOCs and stabilizing global state management with Redux. Improved application stability by reducing runtime crashes through an Observer-pattern-based approach and robust Redux state management. Increased platform reliability by authoring and maintaining Jest test suites for core React components to catch regressions early. Improved data retrieval efficiency by developing optimized REST endpoints and Node.js/Express middleware. Reduced relational database bottlenecks by designing and optimizing complex queries in MySQL to improve query execution time.

Jr Front-End Developer at Overnix Technologies

September 1, 2019 - December 1, 2021

Developed React Native and web UI for a crypto trading platform. Accelerated app startup by 30% through refined React Native rendering pipelines, strategic code splitting, and optimized native module bridges. Increased dashboard engagement by building responsive TradingView charts, balance trackers, and asset visualizers with pixel-perfect cross-device rendering. Cut feature delivery timelines by 25% by unifying iOS and Android workflows using React Native’s shared architecture and close cross-functional alignment. Expanded platform reach across iOS and Android by developing cross-platform mobile features with React Native.

Junior Front-End Developer (React Native & Web UI) at Overnix Technologies

September 1, 2019 - December 1, 2021

Developed React Native and Web UI for a crypto trading platform. Accelerated app startup by 30% using refined React Native rendering pipelines, strategic code splitting, and optimized native module bridges. Increased dashboard engagement by building responsive trading chart components, balance trackers, and asset visualizers with pixel-perfect cross-device rendering. Cut feature delivery timelines by 25% by unifying iOS and Android workflows via a shared React Native architecture and tight cross-functional alignment. Expanded platform reach across iOS and Android by implementing cross-platform mobile features in React Native.