Senior C# Full-Stack Engineer — AI Data & Infrastructure
About this role
About the Role What if your C expertise could directly shape the systems that power the world's most advanced AI models? We're looking for a Senior C Full-Stack Engineer to design and build the data pipelines, annotation tooling, and evaluation infrastructure that leading AI labs depend on to train and improve next-generation AI. This is a fully remote contract role working on real production systems — not toy problems. You'll collaborate with data, research, and engineering teams at the frontier of AI development, solving genuinely hard infrastructure and systems challenges at scale. - Organization: Alignerr - Type: Hourly Contract - Location: Remote - Commitment: 20–40 hours/week What You'll Do - Design, build, and optimize high-performance C systems 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, production-ready fixes - Participate in synchronous design reviews to iterate on system architecture and implementation decisions Who You Are - Full-stack developer with a strong systems programming background and deep C expertise - 3–5+ years of professional experience writing production C code with a focus on modern standards - Solid understanding of performance optimization, concurrency (threading, atomics), and memory safety - Clear and precise written and verbal communicator — you can articulate technical decisions confidently - Native or fluent English speaker - Available to commit 20–40 hours per week consistently Nice to Have - Prior experience with data annotation, data quality, or evaluation systems - Familiarity with AI/ML workflows, model training pipelines, or benchmarking systems - Experience with distributed systems or developer tooling - Background working with or alongside research teams in fast-moving technical environments Why Join Us - Work directly on cutting-edge AI systems used by leading research labs - Fully remote and flexible — structure your work around your life - Freelance autonomy with the depth and impact of high-stakes engineering work - Collaborate with world-class engineers and researchers on problems that actually matter - Potential for ongoing work and contract extension as projects evolve and expand
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