Senior Fullstack Engineer (.NET)

ITConnect Sp. z o.o.; Warszawa; Hybrid; PLN 180,000 - 240,000; Full time

Job summary

ITConnect Sp. z o.o. seeks an experienced Full Stack .NET developer to modernise and expand critical applications used for research and molecule registrations. You will work across UI, APIs, and data layers, migrating legacy systems to current .NET versions and strengthening Azure infrastructure.

You will implement new features, improve CI/CD pipelines with GitHub Actions, and contribute to testing, security, and observability. A self-driven, collaborative mindset is essential.

Qualifications

• Several years of professional experience in full stack software development.
• Strong hands-on experience with C# and .NET, including migrations to newer versions.
• Experience with Oracle databases, SQL, and data access.
• Hands-on Azure experience and CI/CD pipelines, preferably GitHub Actions.
• Broad understanding of software architecture, security, testing, observability, deployment, and operations.
• Self-driven, responsible, and capable of working across teams.

Responsibilities

• Develop, maintain, and improve business-critical full stack applications.
• Modernise legacy applications and migrate solutions to current versions of .NET.
• Work across UI, backend services, APIs, and data sources.
• Design and implement new functionality for molecule and research entity registrations.
• Establish and improve Azure infrastructure for modernised and existing apps.
• Create and maintain CI/CD pipelines using GitHub Actions.
• Improve engineering quality through automated testing, code reviews, secure development, monitoring, and documentation.
• Support apps across their lifecycle balancing maintenance, stability, debt reduction, and new features.
• Collaborate with teammates to deliver robust, scalable software solutions.

Skills

C# / .NET

Full stack development

REST APIs

Software architecture

Security practices

Code reviews

Observability

Tools

GitHub Actions

Azure

Oracle SQL

CI/CD tooling

Job description

Develop and modernise business-critical full stack applications supporting the registration of new molecules and other research entities.

• 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