Lead Backend Engineer - AI Tooling

About The Role

What if your Python expertise could directly shape the infrastructure powering next-generation AI models? We're looking for a Senior Backend Engineer to design and build the data pipelines, annotation systems, and evaluation tooling that leading AI labs depend on to train and improve their most important models.

This is a fully remote contract role with flexible hours — real, high-impact engineering work on production systems at the frontier of AI development.

• Organization: Alignerr
• Type: Hourly Contract
• Location: Remote
• Commitment: 20–40 hours/week

• Design, build, and optimize high-performance Python systems supporting AI data pipelines and evaluation workflows
• Develop backend services and full-stack tooling for large-scale data annotation, validation, and quality control
• Architect robust APIs (REST/GraphQL), design database schemas, and implement authentication and authorization flows
• 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 solutions
• Lead synchronous code reviews and contribute to system design decisions

• Native or fluent English speaker with strong written and verbal communication skills
• Experienced full-stack developer with a strong systems programming background
• 5+ years of professional experience writing production Python backend services
• Deep familiarity with modern web frameworks and strict type enforcement patterns
• Comfortable leading code reviews and driving system design discussions
• Able to commit 20–40 hours per week with reliable availability

• 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
• Background working directly with or alongside AI research teams

• Work on real production systems used by leading AI labs — not toy projects
• Fully remote and flexible — structure your hours around your life
• Freelance autonomy with the depth and challenge of high-stakes engineering work
• Make a tangible impact on AI systems that are shaping the future of technology
• Potential for ongoing work and contract extension as new projects launch