Senior C# Infrastructure Engineer - Data Pipelines

C# Infrastructure Engineer — Data Pipelines (AI Training) About The Role What if your C# skills could directly shape the infrastructure powering next-generation AI systems used by millions of people? 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 sit at the heart of cutting-edge AI development. This is a fully remote, flexible contract role working alongside leading AI labs on real production systems and high-impact engineering challenges. If you're a senior engineer who thrives on performance, scalability, and building things that actually matter — this is the role for you. Organization: AlignerrType: Hourly ContractLocation: RemoteCommitment: 20–40 hours/week What You'll Do Design, build, and optimize high-performance C# systems supporting AI data pipelines and evaluation workflowsDevelop full-stack tooling and backend services for large-scale data annotation, validation, and quality controlImprove reliability, performance, and resilience across existing C# codebasesCollaborate with data, research, and engineering teams to support model training and evaluation workflowsIdentify bottlenecks and edge cases in data and system behavior, and implement scalable, production-ready fixesParticipate in synchronous design reviews to iterate on architecture and implementation decisions Who You Are Native or fluent English speaker with strong written and verbal communication skillsFull-stack developer with a deep systems programming background5+ years of professional experience writing production-grade C#Proven experience building streaming data pipelines using asynchronous streams and reactive programming patternsSkilled at optimizing I/O-bound operations and implementing resilient retry and fault-tolerance strategies for distributed data ingestionAble to commit 20–40 hours per week with reliability and consistency Nice to Have Prior experience with data annotation, data quality pipelines, or model evaluation systemsFamiliarity with AI/ML workflows, model training, or benchmarking infrastructureExperience with distributed systems architecture or developer tooling Why Join Us Work on cutting-edge AI projects alongside leading research labsFully remote and flexible — work when and where it suits youFreelance autonomy with the structure and impact of meaningful, production-level workMake a direct, tangible contribution to the infrastructure powering next-generation AIPotential for ongoing work and contract extension as new projects launch