Sr .NET Software Development Engineer

Job Description

Hardware engineers live inside their CAD tools. Solidworks and Siemens NX are where designs are born, iterated, and finalized-and our job is to meet them there. As a .NET / C# Engineer on the Plugin Integrations team, you'll build and maintain the plugins that bring Duro's PLM platform directly into these tools, giving hardware teams seamless access to parts libraries, BOMs, change orders, and lifecycle management without ever leaving their design environment.

These plugins are built in .NET/C# and communicate with Duro's core platform through our Graph

QL API. You'll own features end-to-end within the plugins-from understanding how a mechanical engineer uses Solidworks daily, to implementing the integration, to shipping it. You'll work under our Plugin Integrations team lead and alongside other integration engineers, contributing to a codebase that directly impacts how hardware teams experience Duro.

Your primary environment is Windows-that's where the CAD tools run. But Duro's core stack is Node.js and Type Script, and you'll occasionally work across that boundary: running the API locally on a Mac, working within WSL, or contributing to shared tooling. We're looking for someone rooted in .NET who's comfortable crossing into our broader ecosystem when the work calls for it.

A Day in the Life

* Build and deliver features within our Solidworks and Siemens NX plugins-translating product requirements into clean, maintainable .NET/C# code that integrates tightly with Duro's Graph

QL API

* Work with the CAD plugin SDK APIs for Solidworks and Siemens NX-understanding their event models, UI extension points, and data structures to build integrations that feel native to the design environment

* Consume and integrate with Duro's Apollo Graph

QL API-querying and mutating parts, BOMs, change orders, and lifecycle data from within the plugin layer

* Debug and troubleshoot across the integration boundary-tracing issues from the .NET plugin through HTTP/Graph

QL to the Node.js backend and back

* Maintain and improve existing plugin functionality-addressing bugs, improving performance, and keeping integrations current as both the CAD platforms and Duro's API evolve

* Collaborate with your team lead and fellow integration engineers on architecture decisions, code reviews, and shared patterns across the plugin codebase

* Occasionally work within the broader Duro stack-running the Node.js/Type Script API locally via WSL or macOS, contributing to shared utilities, or testing API changes that affect the plugin layer

* Engage with product and design to understand how hardware engineers actually use these CAD tools-the best integrations are invisible, and that requires empathy for the end user's workflow

Qualifications

Who We're Looking For

* 4-6 years of experience in software engineering with a strong focus on .NET and C#

* Experience building plugins, extensions, or integrations for desktop applications-ideally CAD tools like Solidworks, Siemens NX, AutoCAD, or similar

* Comfort working with REST and Graph

QL APIs as a client-you know how to consume, query, and debug API integrations from the plugin side

* Solid understanding of Windows development environments, Visual Studio, .NET Framework and .NET Core, and desktop application lifecycle

* Willingness to work across ecosystems-comfortable in WSL, familiar with Node.js/Type Script enough to run, test, and contribute to the broader Duro stack when needed

* A product-minded approach-you care about how the integration feels to the end user, not just whether it technically works

How We Build

We build where our users are.

Hardware engineers don't want to leave their CAD tools to manage their product data. The best PLM integration is one they barely notice-it just works, right where they're already designing. That's what you're building.

At Duro, AI is central to how we work. Every engineer runs Claude Code as their primary development environment, orchestrating sub-agents, structuring context, and shaping outputs into production-ready systems. Every engineer is equipped with a Claude Max 20× plan-not as a perk, but as a requirement. For plugin development, this means AI-assisted C# development, rapid prototyping of integration patterns, and using AI to navigate complex CAD SDK documentation-all guided by an engineer who understands the problem domain deeply enough to validate the output.

We care less about whether you can recite the Solidworks API reference from memory. We care whether you can understand a mechanical engineer's workflow, identify where Duro should seamlessly appear in that workflow, and build an integration that feels like it was always there.

Nice to Have

* Direct experience with the Solidworks API or Siemens NX Open API

* Experience with PLM, PDM, or hardware/manufacturing industry software

* Familiarity with WPF or Win Forms for building plugin UIs

* Background in MVVM or similar patterns for desktop application architecture

* Experience with NuGet package management and .NET…