Full-Stack Engineer (React + .NET) – Modernize & Build APIs

Symphony Solutions; Poland; On-site; PLN 120,000 - 180,000; Full time

Job summary

Symphony Solutions is seeking a Full-Stack Software Engineer (React + .NET) to join our Development Team in Poland. You will work across back-end and front-end, modernizing existing applications and taking ownership of features, with emphasis on clean, maintainable code and pragmatic problem-solving.

Ideal candidates have 3+ years in .NET, strong REST API experience, and solid React + TypeScript skills. You will collaborate with UX, product, QA, and operations to deliver reliable, scalable

Qualifications

• 3+ years of .NET and application development experience.
• REST APIs with ASP.NET Core, .NET Core / .NET MVC, and C#.
• Modern web stack: HTML5, SCSS, TypeScript, React, Redux.
• EF Core, SQL Server, and LINQ.
• CI/CD and source control (Git).
• English at B2 level.
• Experience with AI features or tools integration.
• Familiarity with Azure DevOps, Jenkins, or Octopus.

Responsibilities

• Design, develop, test, and maintain applications using C#, .NET Framework/.NET Core, and modern .NET.
• Modernize legacy .NET architectures and improve existing applications.
• Develop RESTful APIs and microservices, ensure secure authentication and logging.
• Collaborate with cross-functional teams in Agile/Scrum workflows.
• Review code and contribute to engineering standards.
• Ensure clean, maintainable, and testable code with good architecture.
• Work on front-end with React + TypeScript as part of full-stack delivery.
• Participate in CI/CD daily operations and DevOps practices.

Skills

3+ years in .NET

REST APIs with ASP.NET Core

React + TypeScript

EF Core

Git

CI/CD

Azure DevOps / Jenkins / Octopus

English B2

AI integration experience

Tools

Git

Azure DevOps

Jenkins

Octopus

Job description

Symphony Solutions is seeking a Full-Stack Software Engineer (React + .NET) to join our Development Team in Poland. You will work across back-end and front-end, modernizing existing applications and taking ownership of features, with emphasis on clean, maintainable code and pragmatic problem-solving.

Ideal candidates have 3+ years in .NET, strong REST API experience, and solid React + TypeScript skills. You will collaborate with UX, product, QA, and operations to deliver reliable, scalable