Senior .NET Backend Engineer (m/w/d): C#, Domain-Modellierung & KI

We at Yukawa make digitalization in companies productive. We connect hardware, cloud, and AI to digital products for industry and small and medium-sized enterprises. We understand our customers' business in depth and deliver innovation.

Our team comes from physics, mathematics, data science, and software engineering, is small, extremely strong in terms of expertise, and works pragmatically.

For our growing projects, we are looking for an experienced developer personality who not only writes code but also shapes architectures, understands professional domains, and embeds AI where it provides genuine added value.

Aufgaben

As Sr. Software Engineer, you will be the technical anchor in one of our customer projects. You will take responsibility for architecture and implementation of data-intensive, professionally complex applications in the .NET environment with full-stack components in TypeScript/React and a growing AI component. You will work closely with Product Owners, Data Scientists, and domain experts together, help the team grow (Pair Programming, Code Reviews), and ensure that what we build is clean, testable, and maintainable.

• Design and implementation of demanding backend and full-stack solutions in C# / .NET
• Domain modeling of complex rule- and data structures – from requirement to productive systemIntegration of KI models (LLMs, classifiers, recommendation systems) into existing and new applications
• Setup and operation of data- and rule-pipelines, including database design (MS SQL, Oracle, PostgreSQL)
• Responsibility for testing, CI/CD, and code quality
• Pair Programming, Code Reviews
• Influence on technical decisions across project and customer boundaries

Qualifikation

• Minimum 5-10 years of professional software development experience
• Very strong .NET / C# profile at a productive level
• Experience in software architecture and domain modeling of complex business logic
• Practical experience with relational databases (MS SQL, Oracle or PostgreSQL) and data-intensive applications
• Familiarity with cloud (ideally Azure), Docker, Kubernetes, Git, and modern CI/CD pipelines
• Interest and initial experience in integrating KI / LLMs into productive software
• Self-motivated, structured work style and enjoyment of Pair Programming and Code ReviewsGerman conversationally fluent, English fluently
• Communication strength and sovereignty in direct customer contact: You feel comfortable working with the customer team, speaking with domain experts, and representing technical decisions
• Readiness to occasionally be on site at the customer's location (e.g., in NRW)
• German conversationally fluent, English fluently

Benefits

• Unlimited employment contract with Yukawa with the best-of-both-worlds setup: You work deeply in customer projects, but have a stable, strong team behind you
• Hybrid working: predominantly remote, with regular on-site days at the customer and joint Yukawa-team days
• Demanding projects directly in real corporate environments
• KI that runs in production, not just in PowerPoint
• Effective impact at the customer: You will be part of the customer team and shape with them
• Small, strong Yukawa-team as a home base: short distances, plenty of responsibility
• Hight-quality hardware of your choice
• Personal further education budget (conferences, books, certifications)

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