Desktop Developer

Software Engineer (C# / Desktop Systems) - 2 Openings

Hybrid | Vista, CA (2 days onsite / 3 days remote)
Contract with strong long-term potential
Are you a C# engineer who enjoys working close to the hardware-building real products that interact with sensors, devices, and complex systems? This role is not web development. You'll be working on sophisticated Windows desktop software that powers advanced inspection and imaging systems used globally in high-impact environments.
This team is expanding due to growing product demand and a large, complex codebase that values engineers who like depth, longevity, and technical challenge.

What You'll Work On

• Maintain and enhance large-scale Windows desktop applications written primarily in C#
• Develop software that interfaces with embedded systems, sensors, PLCs, and hardware devices
• Support both new product development and sustainment of existing systems with millions of lines of code
• Analyze failures, debug complex issues, and implement durable fixes in a mature codebase
• Collaborate daily with Electrical Engineers, Mechanical Engineers, and Scientists
• Build and improve services, simulators, diagnostics, and tooling
• Contribute to algorithm-driven features involving imaging, signal processing, and data analysis
• Participate in Agile workflows: daily standups, backlog-driven work, code reviews, CI, and TDD

Technical Environment

• C# / .NET (desktop, client-server, multithreaded)
• Windows Services, messaging, real-time data processing
• Interfacing with hardware, sensors, and embedded systems
• Some legacy C++ in the ecosystem
• Messaging systems (e.g., brokered or queue-based architectures)
• CI/CD pipelines and automated testing
• Object-oriented design with a focus on maintainability and extensibility

Required Experience

• 8+ years overall software development experience
• 4+ years of C# in production environments supporting products or devices (not web apps)
• Strong understanding of object-oriented design and navigating complex codebases
• Experience with desktop or client-server applications on Windows
• Solid troubleshooting and debugging skills
• Familiarity with Agile, TDD, and continuous integration
• Ability to produce clear technical documentation
• Bachelor's degree in Computer Science or equivalent experience

Best-fit backgrounds: medical devices, imaging systems, industrial controls, hardware-integrated software, sensors, PLCs, or similar product-based environments.

Nice to Have

• Multithreading and real-time systems experience
• Image processing or computer vision exposure (e.g., OpenCV)
• Messaging systems (e.g., RabbitMQ or similar)
• Embedded systems, RTOS, or PLC integration
• Security-focused software development
• Experience refactoring large, legacy systems
• Familiarity with WPF / Prism
• Algorithm development or strong math/engineering foundation
• Interest in AI/ML-enabled tooling or workflows

Why Engineers Like This Team

• Work on physical products that have real-world impact
• Deep, challenging engineering problems (not CRUD or UI-heavy work)
• Strong team culture with long-tenured engineers
• High likelihood of long-term extensions due to the specialized domain knowledge
• Opportunity to grow into future initiatives involving machine learning and advanced analytics
• Hybrid schedule with flexibility once onboarded

Interview Process

• Interactive technical interview with software engineers
• Live problem-solving (e.g., fixing unit tests, working through multidimensional arrays, imaging-style logic)
• Focus on communication, reasoning, and coding-not trivia

This posting is for an existing vacancy
Job Type & Location
This is a Contract position based out of San Marcos, CA.
Pay and Benefits
The pay range for this position is $75.00 - $75.00/hr.
Eligibility requirements apply to some benefits and may depend on your job classification and length of employment. Benefits are subject to change and may be subject to specific elections, plan, or program terms. If eligible, the benefits available for this temporary role may include the following:
Medical, dental & vision
Critical Illness, Accident, and Hospital
401(k) Retirement Plan - Pre-tax and Roth post-tax contributions available
Life Insurance (Voluntary Life & AD&D for the employee and dependents)
Short and long-term disability
Health Spending Account (HSA)
Transportation benefits
Employee Assistance Program
Time Off/Leave (PTO, Vacation or Sick Leave)
Workplace Type
This is a fully onsite position in San Marcos,CA.
Application Deadline
This position is anticipated to close on May 1, 2026.
>About TEKsystems:
We're partners in transformation. We help clients activate ideas and solutions to take advantage of a new world of opportunity. We are a team of 80,000 strong, working with over 6,000 clients, including 80% of the Fortune 500, across North America, Europe and Asia. As an industry leader in Full-Stack Technology Services, Talent Services, and real-world application, we work with progressive leaders to drive change. That's the power of true partnership. TEKsystems is an Allegis Group company.

The company is an equal opportunity employer and will consider all applications without regards to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.

About TEKsystems and TEKsystems Global Services

We're a leading provider of business and technology services. We accelerate business transformation for our customers. Our expertise in strategy, design, execution and operations unlocks business value through a range of solutions. We're a team of 80,000 strong, working with over 6,000 customers, including 80% of the Fortune 500 across North America, Europe and Asia, who partner with us for our scale, full-stack capabilities and speed. We're strategic thinkers, hands-on collaborators, helping customers capitalize on change and master the momentum of technology. We're building tomorrow by delivering business outcomes and making positive impacts in our global communities. TEKsystems and TEKsystems Global Services are Allegis Group companies. Learn more at TEKsystems.com.

The company is an equal opportunity employer and will consider all applications without regard to race, sex, age, color, religion, national origin, veteran status, disability, sexual orientation, gender identity, genetic information or any characteristic protected by law.