Principal Systems Engineer (C++) - AI Infrastructure

About the job Principal Systems Engineer (C++) — AI Infrastructure About The Role What if your systems engineering expertise could directly shape the infrastructure powering the world's most advanced AI models? We're looking for a Principal C++ Systems Engineer to design and build the high-performance data pipelines, annotation tooling, and evaluation infrastructure that leading AI labs depend on to train and improve next-generation models. This is a fully remote contract role working on real production systems — not toy projects. You'll be embedded in high-impact engineering workflows alongside researchers and engineers 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 C++ systems supporting large-scale AI data pipelines and evaluation workflows Develop full-stack tooling and backend services for data annotation, validation, and quality control at scale Improve reliability, performance, and memory safety across existing production C++ codebases Collaborate with data, research, and engineering teams to support model training and evaluation infrastructure Identify bottlenecks and edge cases in system and data behavior — then implement clean, scalable fixes Participate in synchronous design reviews to iterate on architecture and implementation decisions Who You Are Native or fluent English speaker with strong written and verbal communication skills Full-stack developer with a deep systems programming background and production C++ experience 5+ years writing production-grade C++ for large-scale, high-performance systems Advanced knowledge of build system architecture and package management strategies Experienced in designing reliable systems with rigorous error handling and memory safety practices — including the use of memory sanitizers Able to commit 20–40 hours per week with professional reliability 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 Background in distributed systems design or developer tooling Why Join Us Work directly on production systems used by leading AI research labs Fully remote and async-friendly — work from wherever you do your best thinking Freelance autonomy with the structure and consistency of meaningful long-term projects Make a tangible impact on the infrastructure that trains and evaluates frontier AI models Potential for ongoing work and contract extension as new projects launch