Service development: Implementation and maintenance of cross-product core services for all everii products – e.g., OCR services for invoice processing from PDFs using AI, eInvoice services for electronic invoicing in various countries, and other product-related services.
Service encapsulation: Extracting functionality from individual products and providing it as standalone, reusable services.
AI & Innovation: Active use of AI tools and agents to support development processes.
Quality & Testing: Automated tests, code reviews and continuous improvement of code quality and developer experience.
APIs & Integrations: Development and enhancement of REST and GraphQL APIs, including authentication (OAuth, JWT) and documentation (Swagger/OpenAPI).
Operations & Monitoring: Responsibility for stable and secure services including monitoring (Grafana, Victoria Logs & Metrics) and troubleshooting across our CI/CD pipelines (GitHub Actions, Docker).
Technical concepts: Creating and implementing technical concepts as well as actively discussing architecture and solution approaches within the team.
Collaboration: Close collaboration within the development team and technical exchange on architecture and solution approaches.

Solid backend experience with ASP.NET Core (including Entity Framework Core, Hangfire) – you know the .NET ecosystem and write C# with conviction.
Confident use of Git and IDEs such as Visual Studio, VS Code or JetBrains Rider.
Knowledge of PostgreSQL, MS SQL or other relational databases.
Experience with REST and GraphQL APIs as well as API authentication (OAuth, JWT) and documentation (Swagger/OpenAPI).
Experience with Hangfire (.NET).
Knowledge of performance optimization and caching strategies.
Comfortable and confident using AI tools and agents.
Routine with automated testing as well as GitHub Actions, Docker and container-based deployment.
Basic knowledge of working with Linux servers and container-based setups.
Ideally you have already contributed to a production-deployed SaaS product.
Clear communication skills, giving and receiving feedback, and conducting constructive discussions.

Individual development: Room for autonomous work, scope to shape your role and continuous learning.
Smart Work: Modern technical equipment, a hybrid working model and trust-based working hours.
Feel-good atmosphere: Fresh fruit, coffee, chilled drinks and weekly shared breakfasts – located in the heart of Hamburg or Frankfurt.
Tech stack & team: Modern tools and technologies in a product-focused team with short decision-making paths.
Stability: Permanent full-time role, start possible immediately.

Senior Developer – .NET, C#

Key skills