Modernization of Order Management System (OMS) — incremental migration of a large-scale legacy system to a modern technology stack.

Joined the project when the core system was running on VBA with a COM bridge to C# (.NET Framework) for order recalculation. Played a key role in a large-scale architectural transformation:

API Migration: single-handedly migrated the order import module — roughly a third of the entire system — from the legacy monolith to a service layer. The effort spanned approximately one year and involved a complete redesign of data flows. API projects were built on the latest .NET LTS and regularly upgraded to newer versions. JSON:API & Cross-Stack Integration: APIs were built to the JSON:API specification to ensure compatibility with the PHP side of the engineering team. Maintained a custom fork of the JsonApiDotNetCore library, adapted to the project's internal requirements.

Core Recalculation Engine Refactoring: contributed to rewriting the key order recalculation module — removing dependencies on VBA and WinForms, extracting the logic into a cross-platform .NET Standard 2.0 NuGet package.

Backend & Integrations: designed microservices (C#), implemented asynchronous inter-service communication via RabbitMQ, integrated third-party APIs — marketplaces, logistics, and external platforms.

Data: T-SQL — query optimization and stored procedures for high-throughput order processing.

Frontend: contributed to building a new React-based UI to replace the legacy interface.

Tech Stack: C#, .NET (LTS, regularly upgraded), .NET Standard, JSON:API (JsonApiDotNetCore), RabbitMQ, T-SQL, React, REST API, .NET Cryptography, X509

Development of CRM system that processing leads from different funnels and ad platforms, calculate agents bonuses, communicate with leads using WebRTC and so on.

Stack:
C#, ASP.NET, NHibernate, JavaScript, Ext.js, MS SQL, Swagger, AWS, Azure Boards/Repos/Pipelines, Git, WebRTC

Stack:
C#, ASP.NET Core, NHibernate, JavaScript, Angular, MS SQL, Swagger, AWS, Azure Boards/Repos/Pipelines, Git

Was working on two projects:

• Development of proxy API between Customer API + External API and front-end. Within the framework of the project, were processed authorization and authentication , API data collecting and calculating.
• Pharmacy BA Data Warehouse – application for collecting, processing and viewing huge amounts of data about the production and sales of medicines.

Stack:
C#, ASP.NET, Entity Framework, LINQ to SQL, SignalR, JavaScript, VueJS, Highcharts, MS SQL, Swagger, Git