Senior .NET Full-Stack Engineer | C#, React, CI/CD

Synechron; Kraków; On-site; PLN 230,000 - 290,000; Full time

Job summary

Synechron in Kraków is seeking an experienced software engineer to design, develop, and support scalable enterprise solutions built with .NET, React, and SQL Server. You will contribute to robust backend services, modern UI components, and efficient data access patterns in a fast-paced environment.

You’ll work across the full SDLC, mentor teammates, and help drive CI/CD automation while collaborating with product teams and DevOps professionals to deliver high-quality software that improves

Qualifications

• 7+ years of professional experience developing and supporting production applications in the .NET ecosystem.
• Strong proficiency in C#, ASP.NET Core/Web API, and backend development.
• Hands-on experience with React and modern front-end development.
• Advanced knowledge of SQL Server, T-SQL, database design, query optimization, and performance tuning.
• Proven experience with CI/CD.
• Strong understanding of the Software Development Life Cycle (SDLC).
• Excellent troubleshooting, problem-solving, communication, and stakeholder-management skills.

Responsibilities

• Design and implement robust solutions using industry-standard design patterns.
• Analyze business requirements and recommend effective technical improvements.
• Develop scalable and secure backend services using C# and Web API.
• Build dynamic, responsive, and high-performance user interfaces using React.
• Lead UI enhancements to improve user experience, application stability, and performance.
• Design and optimize databases, queries, and stored procedures using SQL Server and T-SQL.
• Contribute to software architecture, technical design, and application prototypes.
• Drive CI/CD automation and continuously improve the DevOps lifecycle.
• Participate across the complete SDLC—from requirements gathering through deployment and maintenance.
• Manage changes through the service management lifecycle.
• Troubleshoot and resolve complex production issues in a high-pressure environment.
• Work closely with customers to understand their needs and deliver timely, effective solutions.

Skills

C#

ASP.NET Core/Web API

React

SQL Server

CI/CD

SDLC

Troubleshooting

Communication

Job description

Synechron in Kraków is seeking an experienced software engineer to design, develop, and support scalable enterprise solutions built with .NET, React, and SQL Server. You will contribute to robust backend services, modern UI components, and efficient data access patterns in a fast-paced environment.

You’ll work across the full SDLC, mentor teammates, and help drive CI/CD automation while collaborating with product teams and DevOps professionals to deliver high-quality software that improves