Senior Python Full-Stack Engineer — AI Data & Infrastructure

About The Role What if your Python expertise could directly shape the infrastructure behind the world's most advanced AI systems? We're looking for a Senior Python 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 next-generation models. This is a fully remote contract role with meaningful, high-impact work — not filler tasks. You'll be working on real production systems alongside data, research, and engineering teams 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 Python systems supporting AI data pipelines and model evaluation workflows • Develop full-stack tooling and backend services for large-scale data annotation, validation, and quality control • Improve reliability, performance, and safety across existing Python codebases • Collaborate with data, research, and engineering teams to support model training and evaluation workflows • Identify bottlenecks and edge cases in data and system behavior, and implement scalable fixes • Participate in synchronous design reviews to iterate on system architecture and implementation decisions Who You Are • Native or fluent English speaker with clear written and verbal communication skills • Experienced full-stack developer with a strong systems programming background • 5+ years of professional experience writing production-grade Python • Deep understanding of performance optimization and concurrency — asyncio, multiprocessing, threading • Comfortable with type safety tooling such as Pydantic and mypy • Proven track record building robust backend services (FastAPI, Django) or scalable data pipelines • Able to commit 20–40 hours per week consistently Nice to Have • Prior experience with data annotation, data quality systems, or model evaluation infrastructure • Familiarity with AI/ML workflows, model training pipelines, or benchmarking systems • Experience with distributed systems or developer tooling Why Join Us • Work on cutting-edge AI infrastructure alongside leading research labs • Fully remote and flexible — work when and where it suits you • Freelance autonomy with the depth and impact of a senior engineering role • Contribute directly to systems that shape how next-generation AI models are built and evaluated • Potential for ongoing work and contract extension as new projects launch