Senior Backend Engineer (C#) - AI Data Platform
About this role
About the Role What if your C expertise could directly shape the infrastructure powering the next generation of AI? We're looking for a Senior Backend 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 their models. This is a fully remote contract role with meaningful technical scope. You'll work on real production systems — not toy projects — alongside data, research, and engineering teams at the frontier of AI development. - Organization: Alignerr - Type: Hourly Contract - Location: Remote - Commitment: 20–40 hours/week What You'll Do - Design, build, and optimize high-performance backend systems in C supporting AI data pipelines and evaluation workflows - Develop backend services and tooling for large-scale data annotation, validation, and quality control - Build and maintain RESTful APIs and RPC services for reliable inter-service communication - Integrate with cloud-native data services and orchestrate workflows via message bus architectures - Improve reliability, performance, and safety across existing C codebases - Identify bottlenecks and edge cases in data and system behavior, then implement scalable, durable fixes - Collaborate with data, research, and engineering teams to support model training and evaluation workflows - Participate in synchronous design reviews to iterate on architecture and implementation decisions Who You Are - 5+ years of professional experience building scalable backend services in C - Strong systems programming background with full-stack exposure - Mastery of modern frameworks for building RESTful APIs and RPC services - Experienced with cloud-native data services and message bus / event-driven architectures - Native or fluent English speaker with clear written and verbal communication skills - Self-directed and reliable — able to commit 20–40 hours per week and deliver consistently - Sharp eye for performance bottlenecks, edge cases, and system-level failure modes Nice to Have - Prior experience with data annotation, data quality pipelines, or model evaluation systems - Familiarity with AI/ML workflows, model training, or benchmarking infrastructure - Experience with distributed systems, developer tooling, or data orchestration platforms Why Join Us - Work on cutting-edge AI infrastructure projects alongside leading research labs - Fully remote and flexible — work from anywhere, on a schedule that suits you - Freelance autonomy with the structure and purpose of high-impact engineering work - Make a direct, tangible contribution to the systems that shape how AI models are built and evaluated - Potential for ongoing work and contract extension as new projects launch
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