C++ Developer — Internal Tooling & Optimization (AI Infrastructure) About The Role What if your C++ expertise could directly shape the infrastructure that powers the world's most advanced AI systems? We're looking for a Senior C++ Full-Stack Engineer to build and optimize the high-performance tooling data pipelines and evaluation systems that leading AI labs depend on every day. This is a fully remote contract role working on real production systems — not toy projects. You'll collaborate with data research and engineering teams at the frontier of AI development tackling genuinely hard systems problems with meaningful impact. 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 Profile and refactor existing C++ codebases to eliminate bottlenecks and improve reliability performance and safety Embed scripting languages within C++ applications to create flexible extensible internal tools Identify edge cases and failure modes in complex data and system behavior — then implement scalable fixes Collaborate with research and engineering teams to align tooling with model training and evaluation needs Participate in synchronous design reviews to iterate on system architecture and implementation decisions Who You Are 3–5+ years of professional experience writing production-grade C++ Strong full-stack developer background with a deep systems programming foundation Experienced at embedding scripting languages (Python Lua etc.) within C++ applications to build flexible tooling Skilled at profiling and optimizing data processing pipelines — you know where the slowdowns hide Clear confident communicator in written and verbal English Self-directed and reliable — you can deliver quality work with minimal hand-holding Able to commit 20–40 hours per week on a consistent basis Nice to Have Prior experience with data annotation data quality pipelines or evaluation systems Familiarity with AI/ML workflows model training infrastructure or benchmarking pipelines Experience with distributed systems developer tooling or internal platform engineering Background contributing to or reviewing large long-lived C++ codebases Why Join Us Work directly on cutting-edge AI infrastructure alongside leading research labs Fully remote and async-friendly — work from wherever you do your best work Freelance autonomy paired with meaningful technically challenging assignments Make a tangible impact on the systems that train and evaluate next-generation AI models Potential for ongoing work and contract extension as new projects launch