Lead Backend Engineer - AI Tooling

Lead Backend Engineer — AI ToolingAbout The RoleWhat if your Python expertise could directly shape the infrastructure that powers the world's most advanced AI systems? We're looking for a senior backend engineer to build and lead the data pipelines, annotation tooling, and evaluation infrastructure that leading AI labs depend on to train and improve their models.This is a fully remote contract role working on real production systems at the cutting edge of AI development. If you're a senior engineer who wants meaningful, high-impact work — not another CRUD app — this is it.Organization: AlignerrType: Hourly ContractLocation: RemoteCommitment: 20–40 hours/weekWhat You'll DoDesign, build, and optimize high-performance Python systems supporting AI data pipelines and model evaluation workflowsDevelop backend services and full-stack tooling for large-scale data annotation, validation, and quality controlArchitect robust APIs (REST/GraphQL), design database schemas, and implement authentication and authorization flowsImprove reliability, performance, and safety across existing Python codebasesIdentify bottlenecks and edge cases in data and system behavior, then implement scalable, production-ready fixesCollaborate with data, research, and engineering teams across model training and evaluation workflowsLead synchronous design and code reviews — driving decisions that shape the architecture of critical AI systemsWho You AreNative or fluent English speaker with strong written and verbal communication skillsFull-stack developer with a deep systems programming background and 5+ years writing production Python backend servicesFluent in modern Python web frameworks with strict type enforcement patternsExperienced architecting scalable APIs, data schemas, and auth systems in production environmentsA natural leader in code reviews and system design sessions — you can articulate decisions clearly and bring others alongAble to commit 20–40 hours per week on a reliable, ongoing basisNice to HavePrior experience with data annotation, data quality pipelines, or AI evaluation systemsFamiliarity with AI/ML workflows, model training, or benchmarking infrastructureExperience with distributed systems, developer tooling, or platform engineeringWhy Join UsWork directly with leading AI labs on systems that influence next-generation model developmentFully remote and flexible — work from wherever you do your best workFreelance autonomy with the structure and stability of ongoing, project-based engagementMake a real, measurable impact on the infrastructure behind some of the most advanced AI in the worldPotential for extended engagement and expanded scope as projects grow