.Net Developer

Billennium is a global technology company with over 20 years of experience, committed to innovation and empowering businesses. As an employer, we offer a supportive, growth-focused environment where collaboration and creativity thrive. Join us to shape the future of technology together!

We are looking for a .NET Developer to join our team and support the development of advanced digital solutions for a global client from the life sciences industry.

In this role, you will contribute to the development of a secure platform supporting scientific and diagnostic processes. You will work on backend applications responsible for managing and processing business-critical data in a regulated environment, collaborating with experienced engineers and contributing to high-quality software solutions.

What you will do

• Develop and maintain backend applications using .NET technologies
• Implement new features and improve existing functionalities following Domain-Driven Design (DDD) principles
• Build and maintain Web APIs and GraphQL-based services
• Create and maintain unit and integration tests
• Support application upgrades and modernization initiatives
• Analyze and estimate development tasks
• Participate in code reviews and contribute to improving code quality
• Collaborate with developers, testers, and business stakeholders in an Agile environment
• Troubleshoot issues and optimize application performance

What we are looking for

• 3+ years of commercial experience in .NET development
• Strong knowledge of C#, .NET Core/.NET 7, and ASP.NET Core
• Experience developing backend applications and REST APIs
• Knowledge of GraphQL, including working with queries and mutations
• Experience with SQL Server and relational databases
• Practical experience with unit and integration testing
• Familiarity with MSTest, NSubstitute, or similar testing frameworks
• Understanding of Dependency Injection and ASP.NET Core fundamentals
• Basic knowledge of Authentication and Authorization mechanisms
• Experience working with Git
• Familiarity with AWS services, ideally Amazon S3
• Experience working in Agile teams
• Good analytical and problem-solving skills
• Good communication skills and proactive attitude
• Fluent English

Nice to have

• Experience with Domain-Driven Design (DDD)
• Experience with GraphQL subscriptions
• Experience in healthcare, life sciences, pharmaceutical, or other regulated industries
• Familiarity with CI/CD practices

Perks and benefits (our offer )

• Comprehensive benefits – enjoy Udemy for Business, private medical care, Multisport card, veterinary package, language lessons, and shopping vouchers
• Flexibility – adaptable working hours and remote/hybrid work options
• Career growth – development opportunities and access to training within partnerships with Microsoft, AWS, Snowflake, Salesforce & more
• Global collaboration – work with an international team
• Innovative environment – contribute to impactful solutions supporting the life sciences industry
• Engaging community – team-building events, CSR initiatives, and hackathons
• Annual company event in Mazury
• Welcome pack to kick off your journey with us

Tech Stack: C#, .NET 7, .NET Core, ASP.NET Core, Web API, GraphQL, SQL Server, MSTest, NSubstitute, Domain-Driven Design (DDD), Integration Testing, Dependency Injection, Authentication & Authorization, Amazon S3, Git, Agile.