Freelance Net Wpf Developer Jobs in Wisconsin (NOW HIRING)

Location: Neenah, WI (Onsite 5 days a week) 

Duration: 4–5 month contract

About the Role

We're looking for a Senior .NET / WPF Developer to join an onsite team building and enhancing a laboratory information management and instrument integration system. You'll own the development of a complex desktop application spanning instrument communication, data processing workflows, and reporting — working directly with engineering, product, and QA stakeholders in an Agile environment. If you thrive in device-connected, data-intensive environments and enjoy solving real-world integration challenges, this role is worth a close look.

Key Responsibilities

Application Development (approx. 80%)

• Design and develop a WPF-based desktop application using a modular, scalable architecture
• Build and enhance workflows supporting lab data capture, calibration, measurement, review, and reporting
• Implement multithreading and async programming patterns for real-time instrument interaction and responsive UI behavior
• Develop data access, offline data handling, synchronization, and upload capabilities
• Enable data export, reporting, and printing functionalities

Device & Instrument Integration (approx. 20%)

• Implement device integration frameworks for multiple laboratory instruments and peripheral devices
• Develop device management and configuration modules, including health checks, status monitoring, thresholds, and communication settings
• Handle serial communication and device connectivity using COM protocols, device APIs, and SDKs

Collaboration & Quality

• Partner with engineering, product, and QA teams on architecture, testing strategy, and deployment planning
• Perform end-to-end validation, integration testing, and issue resolution across device and application workflows

Qualifications

Required

• 5–8 years of software development experience
• Strong proficiency in WPF and desktop UI development
• Solid experience with C# and .NET Core / .NET Framework
• Hands-on experience with serial communication and COM port-based integrations
• Strong understanding of multithreading and async programming using Task and async/await
• Experience integrating hardware devices through APIs, SDKs, or communication protocols
• Knowledge of database access technologies such as ADO.NET or ORMs
• Experience with modular application architecture and desktop application design
• Strong problem-solving and debugging skills in device-connected environments

Preferred

• Experience with laboratory systems, scientific instruments, or embedded device integrations
• Familiarity with LIMS workflows, sample/result handling, or regulated lab environments
• Knowledge of NI libraries or equivalent integration frameworks
• Experience with installer creation and deployment packaging
• Exposure to offline-first applications and sync mechanisms

Fluid thanks you for your interest in this opportunity. However, only candidates with the required qualifications will be contacted.

Fluid adheres to the principles of equal employment opportunity and affirmative action. We welcome and encourage diversity in our workplace.

Candidates must be eligible to work in the United States.