Senior Fullstack Engineer (.NET)

ITConnect; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Job summary

ITConnect is seeking a senior full stack developer to design, build, and modernise business-critical applications. You will work across UI and backend services, migrate legacy solutions to newer .NET versions, and ensure robust data integration with Oracle databases and SQL.

The role emphasizes Azure infrastructure, CI/CD pipelines with GitHub Actions, and a strong focus on security, testing, observability, deployment, and ongoing improvement. Warsaw-based on-site work expected.

Qualifications

• Several years of professional experience in full stack software development.
• Strong hands-on experience with C# and .NET, including maintaining existing solutions and upgrading or migrating applications to newer .NET versions
• Practical experience with Oracle databases, SQL, data access, and integration between applications and database platforms
• Hands-on experience with Azure, CI/CD pipelines, preferably with GitHub Actions
• A broad understanding of software architecture, application security, testing, observability, deployment, and operational support
• A self-driven working style and the confidence to take responsibility for tasks and solutions

Responsibilities

• Develop, maintain, and improve business-critical full stack applications
• Modernise legacy applications and migrate solutions to current versions of .NET
• Work across application layers, including UI, backend services, APIs,data sources
• Design and implement new functionality that supports the registration of new molecules and other research entities
• Establish and improve Azure infrastructure for both modernised and existing applications
• Create and maintain CI/CD pipelines using GitHub Actions
• Improve engineering quality through automated testing, code reviews, secure development practices, monitoring, documentation, and continuous improvement
• Support applications throughout their lifecycle, balancing maintenance, operational stability, technical debt reduction, and new development

Skills

Full stack development

C# & .NET

Software architecture

Testing & observability

Self-driven

Tools

GitHub Actions

Azure

Oracle databases

SQL

Job description

Develop, maintain, and improve business-critical full stack applications. Modernise legacy applications and migrate solutions to current versions of .NET. Work across application layers, including UI, backend services, APIs, data sources. Design and implement new functionality that supports the registration of new molecules and other research entities. Establish and improve Azure infrastructure for both modernised and existing applications. Create and maintain CI/CD pipelines using GitHub Actions. Improve engineering quality through automated testing, code reviews, secure development practices, monitoring, documentation, and continuous improvement. Support applications throughout their lifecycle, balancing maintenance, operational stability, technical debt reduction, and new development.

• Develop, maintain, and improve business-critical full stack applications
• Modernise legacy applications and migrate solutions to current versions of .NET
• Work across application layers, including UI, backend services, APIs,data sources
• Design and implement new functionality that supports the registration of new molecules and other research entities
• Establish and improve Azure infrastructure for both modernised and existing applications
• Create and maintain CI/CD pipelines using GitHub Actions
• Improve engineering quality through automated testing, code reviews, secure development practices, monitoring, documentation, and continuous improvement
• Support applications throughout their lifecycle, balancing maintenance, operational stability, technical debt reduction, and new development
• Several years of professional experience in full stack software development
• Strong hands-on experience with C# and .NET, including maintaining existing solutions and upgrading or migrating applications to newer .NET versions
• Practical experience with Oracle databases, SQL, data access, and integration between applications and database platforms
• Hands-on experience with Azure, CI/CD pipelines, preferably with GitHub Actions
• A broad understanding of software architecture, application security, testing, observability, deployment, and operational support
• A self-driven working style and the confidence to take responsibility for tasks and solutions