Backend Developer - Data Annotation Systems

[Applicants: Be among the first 25 applicants | Industry: Technology, Information and Internet | Type: Contract | Level: Mid-Senior level] About The JobAlignerrconnects 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, RemoteCommitment:20–40 hours/weekCompensation:Competitive, hourly (based on experience)Role ResponsibilitiesDesign, build, and optimize high-performance systems in Python supporting AI data pipelines and evaluation workflowsDevelop full-stack tooling and backend services for large-scale data annotation, validation, and quality controlImprove reliability, performance, and safety across existing Python codebasesCollaborate with data, research, and engineering teams to support model training and evaluation workflowsIdentify bottlenecks and edge cases in data and system behavior, and implement scalable fixesParticipate in synchronous reviews to iterate on system design and implementation decisionsQualificationsMust-HaveNative or fluent English speakerFull-stack developer experience with a strong systems programming background3-5+ 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.PreferredPrior experience with data annotation, data quality, or evaluation systemsFamiliarity with AI/ML workflows, model training, or benchmarking pipelinesExperience with distributed systems or developer toolingApplication ProcessSubmit your resumeComplete a short technical screeningProject matching and onboarding