.NET Developer

About The Company marketwing GmbH is part of the marketwing GROUP, a direct marketing service provider with more than 15 years of experience and approximately 100 employees. The company supports nonprofit organizations and charitable groups with communications and fundraising services, helping them focus on their missions. Based in the Hanover/Garbsen area, marketwing brings together dedicated colleagues who value collaboration, practical solutions, and work with a positive social impact.

About The Role

We are looking for a C# / .NET 10 / ASP.NET Core Software Developer (m/f/d) to join our fundraising technology team in Garbsen as soon as possible. In this role, you will help develop and enhance a comprehensive web application used by organizations in the fundraising and nonprofit sectors. The platform supports essential processes involving donor, address, campaign, and transaction data, connecting business applications with data processing, reporting, and external systems.

You will work across front-end and back-end development, databases, and APIs in a modern ASP.NET Core and .NET 10 environment. This is an opportunity to contribute to a business-critical product, take ownership of features, and help shape a system that supports meaningful work. We prioritize thoughtful engineering and sustainable solutions over rushed releases, and encourage team members to share ideas and influence the product’s future.

Qualifications

We welcome candidates with different professional backgrounds. An IT apprenticeship, computer science degree, or equivalent practical experience can all provide a strong foundation; a specific degree is not required. You should have solid knowledge of C# and .NET, along with experience developing applications using ASP.NET Core. Experience with relational databases and SQL is important, preferably Microsoft SQL Server and T-SQL.

You should also be familiar with the MVC pattern and data-driven web applications, and have knowledge of front-end technologies such as HTML5, CSS3, and JavaScript or TypeScript. Experience with Git and modern version control practices is expected. Very good German and good English skills are required to communicate effectively with colleagues and contribute to project work.

Experience with Entity Framework Core, REST APIs, external system integrations, ASP.NET MVC, or .NET Framework is helpful, particularly if you have worked on modernizing existing applications. These skills are advantageous but not essential. We value developers who write clear, maintainable code, work independently, approach problems creatively, and enjoy understanding and improving established systems.

Responsibilities

Develop and maintain modern front-end and back-end features using C#, .NET 10, and ASP.NET Core. Design and adapt database structures and data-intensive processes using Microsoft SQL Server. Build, integrate, and maintain web APIs and external interfaces, and extend existing application components as the product evolves.

You will independently implement customer requirements from initial concept through delivery, while collaborating with colleagues to identify effective and maintainable approaches. You will also test and document your work, review existing code structures, and contribute to continuous improvements in application quality, performance, and reliability.

Benefits

This is a permanent, long-term opportunity available on a full-time basis with a 38-hour workweek or part-time, with opportunities for professional growth. Flexible working hours support work-life balance, and remote work may be arranged; the team values in-office collaboration. Employees receive 30 days of vacation and access to special leave policies.

Our development environment includes Rider, GitHub, Codex, internal automation tools, code generation, and automated build and quality checks. You will join a supportive team with flat hierarchies and a relaxed working atmosphere. Additional benefits include free parking or convenient public transportation access, Hansefit membership, bike leasing, office fruit and beverages, a company pension plan, capital-forming benefits, Friday team lunches, and regular company events.

Equal Opportunity marketwing GmbH welcomes applicants from a range of professional and personal backgrounds. We value skills, curiosity, and the contribution each person can make to our team. If you are interested in the role, we encourage you to apply and tell us how your experience could support our work. Please include reference number YF-52527 in your application.