Кирило

KYRYLO LOLENKO
FULL-STACK DEVELOPER
Kyiv, Ukraine [open contact info](look above in the "contact info" section) - [open contact info](look above in the "contact info" section) - LinkedIn - Github

ABOUT ME
Full-Stack Developer with 3 years of commercial experience building scalable web applications using React, Next.js,
and Node.js (NestJS). Specialized in designing modern frontend architectures with React, building high-performance
backend APIs, and improving legacy systems through refactoring, database migration, and architecture optimization.
Strong focus on clean architecture, maintainability, and performance optimization.
Experienced working in Agile teams, participating in architecture discussions, code reviews, and delivering
production-ready features across the entire stack.

SKILLS
TECHNOLOGIES
FRONT-END: JAVASCRIPT (ES6+), TYPESCRIPT, REACT, NEXT.JS, ANGULAR, TAILWIND CSS, HTML, CSS
BACK-END: NODE.JS, NESTJS, REST API, WEBSOCKETS, STRAPI, JWT AUTH, RABBITMQ
DATABASES: MYSQL, POSTGRESQL, MONGODB, SQL SCHEMA DESIGN
DEVOPS/TOOLS: DOCKER, GIT, SWAGGER (OPENAPI), CI/CD, AWS, PROMETHEUS, OPENTELEMETRY
AI: AI AGENTS, LLM APIS
COMPUTER SCIENCE
OOP
MONOLITHIC/DISTRIBUTED ENVIRONMENTS
UNIT/INTEGRATION TESTING
LANGUAGES: ENGLISH - B2, UKRAINIAN-FLUENT

PROFESSIONAL EXPERIENCE
VUZOLL VIRTUAL ASSISTANT | Full-stack Developer MARCH 2026 - PRESENT
I am responsible for the development and maintenance of an existing SOA-based system with event-driven
communication and automated testing.
Contributed to a SOA-based system by decoupling business domains and implementing reliable asynchronous
communication between services using RabbitMQ.
Set up application telemetry and monitoring to improve system observability and simplify troubleshooting
across distributed services.
Implemented a real-time voice-to-voice communication flow for an AI assistant, integrating speech input, AI
processing, and voice responses into a seamless user experience.
ITSUA | Full-stack developer JUNE 2024 - MARCH 2026
Worked on the development and modernization of internal web platforms and real-time applications. Responsible
for architecture refactoring and implementation of scalable frontend and backend solutions.
Migrated backend architecture from MongoDB to MySQL, improving overall platform scalability and reducing
average query response time from ~600ms to <200ms.
Led refactoring of a large-scale React application, reducing technical debt and improving maintainability
Improved product listing page performance and UX, resulting in a 10% increase in conversion rate through
targeted fixes and frontend optimizations
Identified and resolved multiple issues related to asynchronous logic, race conditions, and WebSocket message
handling in a real-time gaming system, reducing runtime errors and improving system stability
MSYPRAVDOM | Full-stack developer SEPTEMBER 2023 - MAY 2024
Developed web platforms for internal and client products using React / Next.js and Node.js (NestJS), delivering
multiple production features across frontend and backend systems
Implemented JWT-based authentication with access/refresh tokens and role-based access control (RBAC),
improving session management, security, and user permission management.
Designed database schemas and implemented backend business logic using NestJS, ensuring scalable API
architecture
EDUCATION
STATE UNIVERSITY OF INFORMATION AND COMMUNICATION TECHNOLOGIES - 2023 - 2025
MASTER'S IN SYSTEMS ANALYSIS
KYIV NATIONAL ECONOMIC UNIVERSITY - 2021 - 2023
BACHELOR'S IN COMPUTER SCIENCE