Senior .NET Developer

PYPL-BONE (PayPal / Braintree + SAP Business One)

About the Project

- Enterprise payment integration project for PayPal; - Integration of Braintree payment gateway into SAP Business One ecosystem; - Started as POC, evolved into production distributed system; - Designed and developed a SAP Business One desktop add-on (WinForms/.NET Framework) and backend services supporting payment workflows. Architecture Overview - SAP Business One Desktop Add-on (.NET Framework 4.8, WinForms); - C#/.NET, ASP.NET Web API, NHibernate, RabbitMQ, MSSQL Server, SAP HANA; - RabbitMQ-based asynchronous processing layer; - Dual database support: SAP HANA and MS SQL Server; - Custom UI (Razor Pages + TypeScript) wallet/checkout.

• Fintech

Responsibilities

- Designed and developed new feature implementations with Web API; - Developed and maintained a SAP Business One add-on enabling end-to-end payment processing workflows via Braintree (PayPal) inside SAP B1; - Researched and implemented payment edge cases: 3D Secure flows (CIT/MIT/3RI), CVV verification behavior, vaulting/tokenization mechanisms, and provider-specific constraints; - Designed and implemented backend APIs integrating desktop SAP B1 client ↔ backend services ↔ external payment provider; supported modernization from .NET Framework 4.8.x to .NET 8; - Built and extended backend services/microservices responsible for payment orchestration (authorization, capture, refund, void) and transaction notifications.

ConstructConnect

About the Project

- NextGen platform development in distributed environment; - Backend API development and integration tasks. Architecture Overview - C#, .NET Core, Web API, NUnit test framework, RabbitMQ, Redis, Auth0, JWT, Management API, Apigee API Management, NHibernate, LINQ, MSSQL, Postman, Google Cloud.

• Construction

Responsibilities

- Backend software development, using .NET Stack (.NET 6, NHibernate, WEB API); - Implemented REST APIs for user provisioning, registration, and authentication-related flows. Product - maintenance and support. New feature implementations; - Integrated Auth0 with JWT-based security; applied clean validation and consistent API error handling; - Delivered with NHibernate, Redis caching patterns, RabbitMQ messaging, and SQL Server performance tuning; - Contributed to maintenance, bug fixing, refactoring, and engineering practices; - Employed DevOps practices (Jenkins, QuickBuild) for efficient deployment; - Ensured code quality using testing tools (NUnit/xUnit) and version control; - Participated in Agile ceremonies and production support.

Donor Agents

About the Project

- Charity platform for Ukrainian blood donors; - Mobile app + admin panel architecture. Architecture Overview - C#, .NET Core, Web API, MVC, Entity Framework 6, LINQ, PostgreSQL, React, HTML/CSS, SonarQube, pgAdmin, Swagger.

• Non-profit

Responsibilities

- Full-stack software development, using .NET Stack (C#, Entity Framework, MVC); - Designed simple modular backend structure and delivered API features for donors/admin flows; - Performed maintenance and bug fixing, improved security measures, and managed database migrations; - Ensured code quality and version control (GitHub, GitLab, GitPod); - Collaborated in Agile environment (JIRA) for project management; - Designed user interfaces with HTML, CSS, Bootstrap, and JavaScript (AJAX, jQuery, AngularJS); - Gained experience with scripting in Python for automation tasks; - Handled DB migrations and schema evolution.

SPA for Car Price Aggregation and Comparison

About the Project

Internal project — SPA for car price aggregation and comparison (data collection + storage + search UI) — web parser for getting car prices. Also, for comparing prices from foreign countries, considering the clearance of cars against prices on AUTO.RIA.

• Automotive

Responsibilities

- Design, implementation of new features, bug fixing; - Designed and implemented a small end-to-end web solution: data collection/parsing, persistence, and UI for search/comparison; - Built Web API endpoints and basic backend logic; performed bug fixing and iterative improvements; - Applied clean modular structure and basic automated tests where suitable; used Git-based workflow; - Ensured code quality and version control (GitHub); - Designed user interfaces with HTML, CSS, Bootstrap, and JavaScript.