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Denis Y.
Senior .Net Engineer

Summary:
●Experienced Backend Software Engineer with 9 years of expertise in .NET development
●Strong foundation in C#, .NET Framework, .NET Core, and .NET 5-8
●Proven track record in Fintech and E-commerce domains
●Expertise in REST API design, CQRS pattern, and microservices architecture
●Skilled in database management with PostgreSQL, MS SQL, SQLite, and Oracle
●Experience with payment system integrations (Stripe, M-Pesa) and shipping services (Sendle)
●Proficient in Entity Framework, Docker, Kafka, and cloud services (Azure)
●Strong focus on delivering high-quality, maintainable software solutions with comprehensive test coverage
• Responsible, dedicated, self-motivated, attentive to details
• Able to work independently, manage priorities, and meet project deadlines
• Aimed at project success and connecting business goals

Certifications:
• Claude Certified Architect – Foundations, Anthropic (2026)
• Skills: AI System Design, Claude Agent SDK, Claude Code configuration, Multi-Agent Orchestration, Tool & MCP design, Prompt Engineering

Technical Skills:
Programming Languages: C#, PowerShell
Frameworks: .NET Framework, .NET Core, .NET 5-8, ASP.NET Web Forms, Entity Framework Core, Aspire
Technologies: REST API, CQRS, Microservices Architecture, Monolithic Architecture, TDD, DDD, Kafka, Docker, Docker Compose, Swagger/OpenAPI, LINQ, AutoMapper, Newtonsoft.Json, OpenCV
Databases: PostgreSQL, MS SQL, SQLite, Oracle
Operating Systems: Windows
Source Control: Git, SourceTree
Other: WinForms, Visual Studio, JetBrains Rider, IIS, Jenkins, Azure, xUnit, NUnit, Moq, Postman, Scrum, API Integration, Stripe API, M-Pesa API, Sendle API

Experience:
February 2025 - Present
Full-Stack Developer at Outsourcing Company
Responsibilities:
●resolved critical bug where parking permit could be sold to two customers if the user switched client during checkout
●improved redirect logic in legacy pages, eliminating double-execution issues and streamlining user flow
●cleaned and refactored log management, fixing exception cascades and enabling permanent detailed logging
●performed targeted optimizations and minor UI tweaks on Web Forms, improving responsiveness and user experience
●wrote and executed regression tests for fixed scenarios to stabilize production behavior
●collaborated with teammates to analyze Oracle queries and optimize data retrieval for high-load permit sales
Technologies: C#, .NET Framework 4.8, ASP.NET Web Forms, Oracle, IIS, LINQ, Visual Studio, NUnit
August 2024 - January 2025
Backend Developer at Outsourcing Company
Responsibilities:
●worked on microservices architecture using the Aspire framework
●configured local development environments using Docker Compose and built service images via Visual Studio
●configured and integrated communication between services utilizing Kafka for message exchange
●implemented efficient storage solutions for player data to support processing and analytics
●ensured seamless service communication via REST API
●participated in optimizing data handling processes to ensure reliability and accessibility
Technologies: C#, .NET Core, Docker, Entity Framework, Kafka, Aspire, Microservices Architecture, NUnit, REST API
September 2023 - December 2024
Backend Developer at Outsourcing Company
Responsibilities:
●implemented and maintained CQRS pattern with Entity Framework for efficient database operations
●designed and performed CRUD operations to manage core business entities
●created and maintained Postman collections to facilitate testing and integration for QA and frontend developers
●integrated M-Pesa payment system to handle loan disbursements and repayments
●collaborated with Kenyan engineers to debug and optimize M-Pesa integration
●achieved 90% unit test coverage for the entire project using NUnit to ensure system reliability
●actively participated in team discussions to improve workflows and resolve challenges
Technologies: C#, .NET Core, Entity Framework, CQRS, NUnit, Postman, M-Pesa API, LINQ, REST API
June 2019 - September 2023
Backend Developer at Outsourcing Company
Responsibilities:
●managed integration of payment (Stripe) and shipping services (Sendle)
●developed and maintained REST API endpoints
●collaborated effectively with other development team members
●participated in team meetings and project planning
●worked with CRUD operations for inventory management
●developed an internal tool to automate and streamline release processes
●implemented functionality for creating tables and block-like diagrams for data visualization and project management
●tracked completion of tasks alongside developer and tester contributions
Technologies: C#, .NET Core, Entity Framework, Stripe API, Sendle API, REST API, LINQ, NUnit, Integration Testing
October 2015 - June 2019
Software Engineer at Outsourcing Company
Responsibilities:
●developed a face detection and recognition module using OpenCV
●managed cross-brand camera integration for CCTV systems
●performed system testing and quality assurance
●built an expandable desktop application for the management and operation of multi-brand CCTV systems
●implemented extensibility to accommodate modules such as face and license plate recognition
Technologies: C#, OpenCV, WinForms

Education:
2011 - 2012
Chernihiv Polytechnic National University
Master's in Computer System and Networks

Languages:
English - Fluent
Ukrainian - Native