Oleksandr

Oleksandr Kyryliuk
Full Stack Developer | React / Next.js / Node.js / TypeScript
Rivne, Ukraine | [відкрити контакти](див. вище в блоці «контактна інформація») | [відкрити контакти](див. вище в блоці «контактна інформація»)
LinkedIn: [відкрити контакти](див. вище в блоці «контактна інформація») | GitHub: github.com/OleksandrKyrylyuk
English: Upper-Intermediate
Summary
Full Stack Developer with 4+ years of commercial experience, with a strong backend foundation in Node.js, Express and Fastify, designing and implementing REST APIs and backend services for production healthcare applications. Comfortable owning features end-to-end — backend services, database design, frontend implementation, testing and production support — and collaborating directly with cross-functional Agile teams.
Hands-on personal experience deploying applications to AWS (EC2, S3, Route53) using Docker and Linux (Ubuntu) server administration over SSH, plus AI/RAG development using OpenAI API, LlamaIndex, Qdrant and vector search.
Key Skills
Backend: Node.js, Express.js, Fastify, REST API design & integration, background jobs (BullMQ)
Databases: PostgreSQL, MySQL, MS SQL Server, Redis, SQL, basic MongoDB (personal project)
Cloud & DevOps: AWS (EC2, S3, Route53 — personal projects), Docker, Linux/Ubuntu server administration (SSH), Jenkins, Git, CI/CD
Testing: Jest, React Testing Library, Unit Testing, Component Testing
Frontend: React, Next.js, TypeScript, JavaScript, Redux, Tailwind CSS, Styled Components, Chart.js
AI / Data: OpenAI API, LlamaIndex, RAG, Embeddings, Vector Search, Qdrant, Drizzle ORM
Processes: Agile Scrum, Code Review, Sprint Planning, Production Support
Professional Experience
Middle Full Stack Developer — Capgemini Engineering2023 – May 2026
Healthcare domain | Team of 7: PM, designer, QA, 2 backend engineers, 2 frontend engineers
• Designed and implemented REST APIs and backend services using Node.js, Express and Fastify, integrated with PostgreSQL, MySQL and MS SQL Server.
• Owned multiple application modules end-to-end — from technical design through backend/frontend implementation, testing, deployment and production support.
• Developed healthcare web application features using React, Next.js, TypeScript and SQL/NoSQL databases on top of the backend services above.
• Investigated and resolved production issues that could not be reproduced locally, using log analysis and cross-team debugging with QA, DevOps and backend engineers.
• Added and maintained unit and component tests with Jest and React Testing Library for critical backend logic, UI components, forms and user flows.
• Built and maintained reusable UI components, shared hooks and typed utilities used across several application modules.
• Converted complex Figma designs into responsive, production-ready UI screens with high design accuracy.
• Improved application performance by optimizing React rendering, reducing unnecessary re-renders, implementing lazy loading and improving data-fetching flows.
• Refactored legacy code, simplified state management and improved component boundaries across complex modules.
• Performed code reviews (3–5 pull requests weekly) using Git and Jenkins CI/CD pipelines, and participated in architecture discussions, technical grooming, estimation and sprint planning.
Junior Frontend Developer — Capgemini EngineeringFeb 2022 – 2023
Healthcare domain
• Implemented React features and responsive UI screens from Figma designs for healthcare web applications.
• Integrated REST APIs and fixed production and functional defects during active sprint development.
• Participated in code reviews, pull requests, QA feedback cycles and Agile Scrum ceremonies.
Pet Project — WorkHelper
AI-powered productivity and work-assistance platform focused on daily workflow automation, information retrieval and AI-assisted search. GitHub: github.com/OleksandrKyrylyuk/workHelper
• Designed the full-stack architecture independently and built the React/Next.js frontend with a Node.js (Fastify/Express) backend.
• Integrated OpenAI API, LlamaIndex, Qdrant, embeddings and vector search for contextual document search and RAG-based retrieval.
• Used Drizzle ORM with a SQL database for structured data management.
• Implemented asynchronous background processing with BullMQ and Redis.
• Containerized the application with Docker for local development and environment setup.
Personal Cloud & Infrastructure Experience
Gained through personal projects (not commercial):
• Provisioned and configured AWS EC2 (Ubuntu), S3 and Route53 for personal project hosting.
• Connected to and administered remote Linux (Ubuntu) servers over SSH.
• Deployed containerized applications to EC2 using Docker.
• Experimented with MongoDB in a small personal project.
Domain Experience
Healthcare applications, medical data workflows, secure data handling, role-based user interfaces, enterprise web applications, production support, Agile delivery.
Education & Certifications
Rivne State University of Humanities
Master’s Degree in Applied Mathematics, 2014
STEP IT Academy
Front-end Development, 2022
STEP IT Academy
Network Technologies and System Administration, 2009