Senior C# Full-Stack Engineer — AI Data & Infrastructure
About this role
About the Role What if your 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 build and optimize the 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, flexible contract role for an experienced engineer who wants to work on real production systems at the frontier of AI — not just maintain legacy code, but architect meaningful infrastructure that matters. - Organization: Alignerr - Type: Hourly Contract - Location: Remote - Commitment: 20–40 hours/week What You'll Do - Design, build, and optimize high-performance C systems that support 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 used in production AI environments - Collaborate closely with data, research, and engineering teams to support model training and evaluation workflows - Identify bottlenecks and edge cases in data and system behavior — then implement scalable, robust fixes - Participate in synchronous design reviews to iterate on architecture and implementation decisions Who You Are - Full-stack developer with a strong systems programming background and deep command of C - 3–5+ years of professional experience writing production-grade C code, with familiarity with modern standards - Solid grounding in performance optimization, concurrency (threading, atomics), and memory safety - 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 without hand-holding - Comfortable navigating complex codebases and making principled architectural decisions under real constraints Nice to Have - Prior experience with data annotation platforms, data quality systems, or evaluation infrastructure - Familiarity with AI/ML workflows, model training pipelines, or benchmarking systems - Experience building distributed systems or developer tooling at scale - Background working alongside research or applied AI teams Why Join Us - Work at the frontier of AI — your code will directly influence how the world's leading models are built and evaluated - Fully remote and flexible — structure your hours around your life, not the other way around - Collaborate with world-class research and engineering teams on genuinely hard problems - Freelance autonomy with the substance of high-impact, technically demanding work - Potential for ongoing work and contract extension as projects evolve and expand
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