.NET Developer

NET Developer (Senior, Viewport Team) About Assai Software Assai Software develops enterprise-grade document and information management solutions for large-scale engineering and infrastructure projects. Its platform helps clients manage complex technical documentation with advanced workflow, control and compliance capabilities.

Following the acquisition of Viewport.ai, Assai is integrating intelligent search and visualization into its ecosystem. Viewport interprets engineering drawings, maintenance records, and technical documents from multiple sources, providing users with context-aware access to information across the full asset lifecycle.

The Role Assai is looking for a Senior .NET Developer to strengthen the Viewport development team. You will work on backend services that power semantic search, contextual linking, and visualization of engineering data. Together with the new Product Owner and Technical Lead, you will help shape the integration of Viewport into the Assai platform.

Key Responsibilities

Design, develop, and maintain backend components using .NET and C#. Work on APIs and services that connect Viewport to Assai's document management system. Collaborate with the Product Owner, Tech Lead, and other engineers to translate requirements into scalable solutions. Implement and improve data processing, indexing, and visualization logic for large technical document sets.

Participate in Agile sprints, code reviews, and continuous improvement efforts. Must-Have Skills 8+ years of experience in .NET development (.NET Core, .NET Framework, ASP.NET Core), with a strong, deep foundation in .NET and ASP.NET. Docker. Good understanding of object-oriented programming, software design principles, and clean code practices.

Understanding of version control (Git). Strongly Desired PostgreSQL Azure Cloud Kubernetes, Helm Charts OpenID Connect, OAuth AI integrations, MCP Entity Framework / EF Core Testing automation (unit/integration testing) GitHub (Actions, Packages, Dependabot, etc.) Observability (OpenTelemetry, Grafana, Prometheus) Bonus Points React Svelte NHibernate TeamCity Java Message buses (RabbitMQ, Kafka) OpenAPI, Swagger Public GitHub portfolio Keycloak Basic familiarity with front-end technologies (HTML/CSS/JavaScript) is a plus.

IIS, SAML are also a plus. Soft Skills & Working Style Proactivity, seniority, agency, and engagement. Clear, structured communication able to understand and convey information well. Willingness to work with some existing legacy code (.NET Framework 4.8) alongside new development, as part of an ongoing deprecation effort not purely greenfield.

Exposure to Agile development methodologies (Scrum preferred). Willingness to learn, take initiative, and work collaboratively in a team setting. Strong bonus: mechanical engineering domain knowledge (technical drawings, CAD systems, 3D models).

Education

Bachelor's degree in Computer Science, Software Engineering or a related discipline. What Assai Offers Salary between €60,000 and €85,000 gross per year, depending on experience. Hybrid working model (Culemborg / Amsterdam office + remote days). International environment with growth opportunities. Technically driven culture focused on quality and innovation.

Direct impact on an evolving AI-driven SaaS platform used by global engineering leaders.