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 next generation of AI? 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 their models. This is a high-impact, fully remote contract role for an experienced engineer who thrives on solving hard systems problems and wants their work to matter 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 that power AI data pipelines and evaluation workflows - Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control - Improve the reliability, performance, and safety of existing C codebases used in production AI research environments - Collaborate 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, production-ready fixes - Participate in synchronous design reviews to iterate on architecture and implementation decisions with top engineering talent Who You Are - Full-stack developer with a strong systems programming background and deep C expertise - 3–5+ years of professional experience writing production-grade C code, with fluency in modern standards - Solid understanding of 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 without hand-holding - Comfortable working asynchronously across distributed teams Nice to Have - Prior experience with data annotation pipelines, data quality systems, or evaluation infrastructure - Familiarity with AI/ML workflows, model training, or benchmarking systems - Experience with distributed systems architecture or developer tooling - Background working with or alongside AI research teams Why Join Us - Work on real, production systems used by leading AI labs — not toy projects - Fully remote and flexible — work from wherever you do your best work - Freelance autonomy with the structure of meaningful, high-stakes engineering work - Collaborate with world-class researchers and engineers on problems that matter - Potential for ongoing work and contract extension as projects evolve and expand
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