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

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 pipelines, or evaluation systems
Familiarity with AI/ML workflows, model training, or benchmarking infrastructure
Experience building distributed systems or developer tooling at scale
Why Join Us
Work on real production systems supporting some of the world's leading AI research labs
Fully remote and flexible — structure your hours around your life
Freelance autonomy with the substance of high-impact, technically challenging work
Contribute directly to infrastructure that shapes how next-generation AI models are built and evaluated
Potential for ongoing work and contract extension as projects grow and expand

Work arrangement
Yes