Senior Fullstack Developer .NET + React

We are looking for a Senior Fullstack Developer to join a new banking project focused on developing a microfactoring platform. The role combines backend development in C#/.NET with frontend development in React , working across microservices and existing applications while contributing to solution architecture, performance optimisation, and high-quality software delivery within a Scrum team.

Responsibilities

• Develop software in C#/.NET

• Develop frontend functionality in React

• Analyse and develop existing code

• Work with legacy applications where required

• Participate in solution architecture

• Design and develop new functionality

• Debug and profile applications

• Analyse application performance

• Work with relational databases and TSQL

• Work with asynchronous communication patterns

• Cooperate closely with Developers, Testers, Analysts and Product Owner

• Participate in Scrum delivery

• Maintain code quality and development standards

Requirements

• Minimum 5 years commercial .NET development experience

• Minimum 3 years commercial React development experience

• Strong C#

• .NET Framework

• .NET Standard

• .NET Core / modern .NET

• React 18+

• Debugging and profiling

• Performance analysis

• DDD

• Clean Code

• SOLID

• Architectural patterns

• Asynchronous communication

• TSQL

• SQL Management Studio

• Visual Studio

• Fluent Polish

• English minimum B2

Nice to have

• Experience developing mobile application views

• Banking or financial services experience

• Automated testing

• Postman

• Playwright

• WCAG

Benefits

• Flexible hybrid model (1 day/week onsite in Warsaw/Gdańsk)

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Solid, competitive salary

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Work in a multinational environment on international projects

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Comprehensive healthcare

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Long-term B2B contract with a stable project pipeline