Backend Developer - Data Annotation Systems

About the JobAlignerr 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.PositionSenior Python Full-Stack Engineer — AI Data & InfrastructureType: 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 decisionsQualificationsMust-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 toolingApplication Process- Submit your resume- Complete a short technical screening- Project matching and onboarding