C# Infrastructure Engineer — Data Pipelines (AI Training)
About The Role
What if your deep C# expertise could directly shape the infrastructure powering the world's most advanced AI systems? We're looking for a Senior C# Full-Stack Engineer to design and build the high-performance data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve next-generation models.
This is a fully remote, versátil contract role for experienced engineers who want meaningful, high-impact work — without the constraints of a full-time position.
Design, build, and optimize high-performance C# systems that power AI data pipelines and evaluation workflows
Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control
Improve reliability, performance, and safety across production C# codebases
Identify bottlenecks and edge cases in data and system behavior — then implement scalable,
resilient fixes
Collaborate with data, research, and engineering teams to support model training and evaluation pipelines
Participate in synchronous design reviews to iterate on architecture and implementation decisions
Who You Are
Native or fluent English speaker with clear written and verbal communication skills
Full-stack developer with a strong systems programming background
5+ years of professional experience writing production-grade C#
Proven track record building streaming data pipelines using asynchronous streams and reactive programming patterns
Experienced optimizing I/O-bound operations and implementing resilient retry policies for distributed data ingestion
Able to commit 20–40 hours per week with reliability and consistency
Nice to Have
Prior experience with data annotation, data quality systems, or evaluation pipelines
Familiarity with AI/ML workflows, model training, or benchmarking infr