Backend Developer - Data Annotation Systems - Full-time / Part-time

About the Job Alignerr connects top technical experts with leading AI labs to build, evaluate, and improve next-generation models. We work on real production systems and high-impact research workflows across data, tooling, and infrastructure. Position Senior Python Full-Stack Engineer — AI Data & Infrastructure Type: Contract, Remote Commitment: 20–40 hours/week Compensation: Competitive, hourly (based on experience) Role Responsibilities - Design, build, and optimize high-performance systems in Python 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 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 reviews to iterate on system design and implementation decisions Qualifications Must-Have - Native or fluent English speaker - Full-stack developer experience with a strong systems programming background - 3-5+ years of professional experience writing production Python. - Experience building asynchronous task queues to handle long-running background jobs. - Proficiency in optimizing database queries for high-read/write applications and serving data via real-time protocols (e.g., WebSockets). - Clear written and verbal communication skills. - Ability to commit 20–40 hours per week. Preferred - Prior experience with data annotation, data quality, or evaluation systems - Familiarity with AI/ML workflows, model training, or benchmarking pipelines - Experience with distributed systems or developer tooling Application Process - Submit your resume - Complete a short technical screening - Project matching and onboarding