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Tymofii Koval

@tymofiikoval

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Experienced .NET developer building scalable payment and distributed web applications.

Ukraine

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What I'm looking for

I seek roles where I can build scalable distributed systems, work on payment or microservices projects, and grow technically in a collaborative, engineering-driven team.

I am a skilled .NET developer with over three years of professional experience building scalable, distributed web applications and payment systems across fintech and media industries.

I combine strong backend development in C# and ASP.NET with practical frontend knowledge in React and Next.js, applying SOLID principles and modern design patterns to produce maintainable, high-performance code.

My background includes designing databases, working with microservice architectures, payment system integration, and performance optimization while maintaining large codebases using domain-driven design and onion architecture.

I have hands-on experience with cloud and container technologies, observability and messaging tools, and have delivered MVPs and widely used solutions such as a hotel booking microservices platform and a marketing attribution service.

Experience

Work history, roles, and key accomplishments

Full Stack Developer

ObserviX

Sep 2025 - Dec 2025 (3 months)

Developed the MVP for a marketing attribution platform using ASP.NET, React and Next.js, deploying on Azure and designing SQL-backed data flows for attribution reporting.

ASP.NET React Next.js Azure SQL C++Frontend Backend

Backend Developer

Entravel

Mar 2025 - Sep 2025 (6 months)

Built microservices for a widely used hotel booking solution, implementing gRPC services, Kubernetes deployments and performance optimizations for high-availability booking flows.

ASP.NET C++gRPC SQL Redis Kubernetes Microservices GraphQL

.NET Developer

Paytiko Ltd.

Sep 2022 - Jan 2025 (2 years 4 months)

Contributed to a large-scale payment system aggregator, implementing integrations and maintaining a distributed codebase using DDD and onion architecture to improve reliability and scalability.

ASP.NET C++EF Core Redis Serilog RabbitMQ Payment Integration Distributed Systems

Full Stack Developer

Tsukat Inc.

May 2022 - Aug 2022 (3 months)

Designed database schemas and implemented backend and frontend features for web applications using ASP.NET, C#, TypeScript and React, delivering maintainable code and performant interfaces.

ASP.NET C++TypeScript EF Core React Next.js SQL Docker

Education

Degrees, certifications, and relevant coursework

Taras Shevchenko National University of Kyiv

Bachelor's Degree, Computer Science

2020 - 2024

Studied Computer Science at the Faculty of Information Technology, completing a bachelor's degree program focused on software development and systems design.