Senior Backend Engineer (C#) - AI Data Platform

About the JobAlignerr connects top technical experts with leading AI labs to build, evaluate, and improve next-generation models. We work on real production systems and high-impact research workflows across data, tooling, and infrastructure.PositionSenior C# Full-Stack Engineer - AI Data & InfrastructureType: Contract, Remote Commitment: 20-40 hours/week Compensation: Competitive, hourly (based on experience)Role Responsibilities- Design, build, and optimize high-performance systems in C# supporting 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 existing C# codebases- Collaborate with data, research, and engineering teams to support model training and evaluation workflows- Identify bottlenecks and edge cases in data and system behavior, and implement scalable fixes- Participate in synchronous reviews to iterate on system

design and implementation decisionsQualificationsMust-Have- Native or fluent English speaker- Full-stack developer experience with a strong systems programming background- 5+ years of professional experience building scalable backend services in C#.- Mastery of modern frameworks for building RESTful APIs and RPC services for inter-service communication.- Experience integrating with cloud-native data services and orchestrating workflows via message bus architectures.- Clear written and verbal communication skills.- Ability to commit 20-40 hours per week.Preferred- Prior experience with data annotation, data quality, or evaluation systems- Familiarity with AI/ML workflows, model training, or benchmarking pipelines- Experience with distributed systems or developer toolingApplication Process- Submit your resume- Complete a short technical screening- Project matching and onboarding$50 - $75 an hour