Senior Fullstack Developer .NET + React

We are looking for a Senior Fullstack Developer (.NET + React) to join a new project focused on developing modern solutions for the financial services sector. The role is approximately 70% backend and 30% frontend, involving C#/.NET, React 18+, T-SQL, microservices, DDD, Clean Code and SOLID. You will develop new functionalities, work with existing and legacy code, contribute to solution architecture, and collaborate with Developers, Testers, Analysts and the Product Owner in a Scrum environment.

Responsibilities

• Development in C# / .NET

• Frontend development in React

• Analysis and development of existing and legacy code

• Solution architecture

• Debugging, profiling and performance analysis

• Development of new functionality

• Work with TSQL and relational databases

• Cooperation with Developers, Testers, Analysts and Product Owner

• Work within Scrum

Requirements

• Minimum 5 years commercial .NET development

• Minimum 3 years commercial React development

• Strong C#

• .NET Framework / .NET Standard / .NET Core / modern .NET

• React 18+

• TSQL

• Debugging and profiling

• Performance analysis

• DDD

• Clean Code

• SOLID

• Architectural patterns

• Asynchronous communication

• SQL Management Studio

• Visual Studio

• Fluent Polish

• English minimum B2

Nice to have

• Financial services / banking experience

• Mobile application views

• Automated testing

• Postman

• Playwright

• WCAG

Benefits

• Flexible hybrid work model (1 day/week on-site in Warsaw/Gdańsk)

• Solid, competitive salary

• Work in a multinational environment on international projects

• Comprehensive healthcare

• Long-term B2B contract with a stable project pipeline