Ярослав

YAROSLAV KOPIIKA
Kriviy Rih, Ukraine
FULL STACK (.NET + JS)
[відкрити контакти](див. вище в блоці «контактна інформація») • [відкрити контакти](див. вище в блоці «контактна інформація»)
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SUMMARY
Full-Stack Developer with 7 years of commercial software development experience,
including 4 years specializing in C#/.NET. Experienced in building and maintaining scalable
order processing systems for retail and supermarket chains using ASP.NET Core, SQL
Server (T-SQL), and JavaScript. Skilled in designing RESTful APIs, developing new
features, maintaining existing systems, and improving application performance and
reliability. Familiar with cloud concepts, containerization, and modern software
development practices.

CORE SKILLS

Languages: C#, JavaScript (ES6), SQL, C++
Backend & Architecture: .NET 8 / Core, ASP.NET Core, Entity Framework Core,
REST API, Microservices, SOLID, Design Patterns, Ocelot, Azure Service Bus,
RabbitMQ
Frontend: JavaScript, React, HTML5, CSS3, LESS, Razor Pages
Databases & Tools: MS SQL Server (T-SQL), MySQL, Git, Docker, SharePoint, K2,
xUnit, NUnit
Graphics: OpenGL

WORK EXPERIENCE
MHP - Software Engineer August 2022 – July 2026

Core Engine & Architecture: Designed and built a scalable EDIN-integrated order
processing engine with flexible XML parsing and validation, streamlining the
onboarding of major retail chains (Auchan, Glovo, Epicenter).
Background Services & Automation: Developed and maintained background C#
Windows Services processing 1M+ documents (SharePoint migration, document
archiving) and handling 200–500 daily PDF generation requests with robust retry
patterns and structured logging.
Modernization: Architected and executed the migration of legacy monolithic .NET
Framework applications to a modern .NET 8 / ASP.NET Core microservices
infrastructure (8+ Ocelot-based services), decreasing infrastructure overhead and
improving API response times.
Frontend & Workflow Systems: Developed dynamic UA/EN localization and UI logic
using JavaScript (ES6) and K2/Nintex workflows, supporting 200–300 daily active
internal users.
Security & API Gateway: Implemented secure token-based authentication
(JWT/OAuth2) and rate-limiting policies across Ocelot API Gateways, enhancing
backend API security and preventing service overload

MHP - Software Engineer August 2022 – July 2026

Web & Enterprise Development: Delivered end-to-end features for custom enterprise
web applications using C#/.NET, JavaScript (ES6), and SQL Server, building responsive
UI components, drag-and-drop file uploaders, and complex backend logic.
Business Process Automation: Streamlined corporate workflows and built dynamic
K2-based enterprise applications, implementing C# backend logic and JavaScript (ES6)
interfaces to support 200–300 daily active users.
Database Optimization & Performance: Optimized critical SQL Server queries, index
strategies, and stored procedures across high-load services, reducing database
response time by ~40% and eliminating peak-load bottlenecks.
Quality & CI/CD: Established automated CI/CD pipelines and unit testing suites using
xUnit/NUnit, increasing overall code coverage to 85% and reducing release bug
reports.
Query Performance & Reliability: Refactored critical SQL Server/MySQL stored
procedures and database logic, directly reducing execution times and preventing
transactional failures during order processing.
Monitoring, Logging & Observability: Integrated centralized structured logging and
telemetry (Serilog), enabling real-time system monitoring and reducing root-cause
investigation time by 35%

Software Developer (Contract) January 2019 – July 2022

Desktop & Special Projects: Developed 2D/3D C++/MFC/OpenGL desktop applications
for quarry operators (visualization and industrial management) and contributed to
native Android features (Java).
Database & Maintenance: Developed and optimized SQL/MySQL queries and stored
procedures, improving execution time and defect resolution across commercial
desktop and web applications under senior guidance.
Performance & Graphics Rendering: Optimized 2D/3D rendering algorithms and spatial
data structures using C++ / OpenGL, achieving smooth 60 FPS performance during
real-time visualization of complex geological quarry models.

EDUCATION

State University of Economics and Technology: Bachelor of Software
Engineering - Graduated June, 2022.

State University of Economics and Technology: Master of Software
Engineering - Graduated January, 2024

LANGUAGES

Ukrainian — Native
English — Upper-Intermediate