Senior C++ Full-Stack Engineer — AI Data & Infrastructure

About this role

About The Role
What if your systems programming expertise could directly shape the infrastructure powering the next generation of AI? We're looking for Senior C++ Engineers to build, optimize, and scale the data pipelines, annotation tooling, and evaluation systems that leading AI labs depend on to train and improve frontier models.


This is a fully remote, flexible contract role for seasoned engineers who thrive on high-performance systems work and want their contributions to have real, measurable impact on cutting-edge 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 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 production C++ codebases
• Identify bottlenecks and edge cases in data and system behavior, and implement scalable, robust fixes
• Collaborate with data, research, and engineering teams to support model training and evaluation workflows
• 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++, with a focus on modern standards (C++17 or C++20)
• Solid command of performance optimization, concurrency (threading, atomics), and memory safety (RAII, smart pointers, sanitizers)
• 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 quality work independently
• Sharp eye for edge cases, system behavior, and long-term scalability

Nice to Have

• Prior experience with data annotation, data quality pipe...