Backend Developer (f/m/d) - .NET at JTL-Software GmbH

Cologne, North Rhine-Westphalia, Germany -

Full Time

Start Date

Immediate

Expiry Date

17 Sep, 26

Salary

0.0

Posted On

19 Jun, 26

Experience

2 year(s) or above

Remote Job

Yes

Telecommute

Yes

Sponsor Visa

Skills

C#, .NET, REST API, GraphQL, Microsoft SQL Server, Automated Testing, Clean Code, AI-assisted development, ASP.NET Core, Entity Framework, Azure, Docker

Industry

Software Development

Description

Your mission JTL is one of the leading providers of e-commerce software in the German-speaking region, with around 450 employees across the group and more than 50,000 customers across a wide range of industries. We develop scalable, flexible solutions for the online retail of the future — from ERP systems to shop and marketplace integrations. As a Backend Developer at JTL, you will help develop and modernize the backend services and business logic that power our software platform. You'll work with modern .NET technologies and contribute to the ongoing evolution of our products toward modular architectures, modern APIs, and cloud-ready solutions. We believe software development is about more than writing code. We value quality, maintainability, collaboration, and continuous learning. AI-assisted development is part of our daily work. Our engineers use tools such as GitHub Copilot, Claude Code, and ChatGPT to support coding, refactoring, debugging, and documentation. We expect you to have experience with these tools or a willingness to learn and use them effectively. Your Responsibilities Develop and maintain backend services and business logic using C# and .NET Contribute to the modernization and continuous improvement of our software platform Design, implement, and maintain REST and GraphQL APIs Improve existing code, data structures, and technical workflows Write automated tests and support quality-focused development practices Participate in code reviews and collaborate with other engineers Work closely with product managers, QA engineers, and frontend developers Your profile Experience developing software with C# and .NET Good understanding of software design and clean code principles Experience working with relational databases, ideally Microsoft SQL Server Experience designing or integrating APIs Ability to work effectively in an existing codebase Experience with automated testing Strong problem-solving and analytical skills Experience with AI-assisted development tools or willingness to adopt them Good German and English communication skills Helpful Experience ASP.NET Core Entity Framework GraphQL Azure Docker Experience with modularization or modernization projects Experience with ERP, e-commerce, or enterprise software Why us? Remote-first within Germany, with the option to work remotely from eligible countries for up to 180 days per year Meal allowance of up to €115 net per month Ergonomic workspace allowance for your home office setup Regular team events, company-wide gatherings, and summer and Christmas parties to stay connected as a remote-first company EGYM Wellpass and JobRad subsidy Financial benefits including capital-forming payments (Vermögenswirksame Leistungen) and a company pension scheme About us JTL is one of the leading providers of e-commerce software in the German-speaking region – with around 450 employees across the group and 50,000 customers from a wide range of industries. We develop scalable, flexible solutions for the online retail of the future – from ERP systems to shop and marketplace integrations. Fairness and respect are part of our everyday practice. Are you committed, curious, and eager to work in a team while taking on responsibility? Are you looking for a job where Monday isn’t the worst day of the week? Then we look forward to receiving your application!

Responsibilities

Develop and maintain backend services and business logic using C# and .NET to modernize the software platform. Design and implement REST and GraphQL APIs while collaborating with cross-functional teams to improve technical workflows.