Job Description

OpenTrain AI is hiring a Backend Engineer to design realistic coding tasks for AI systems, write deterministic verifiers, assess correctness and code quality, and apply secure coding and security review where relevant. This is a part-time, independent-contractor role (~15 hours/week) with pay per accepted task ($30–$100 per hour equivalent). 100% remote (US-based). Responsibilities include building scalable APIs/services, debugging, code reviews, and implementing verification criteria. Ideal background includes strong backend experience in Python, Java, Node.js, Go, Rust, TypeScript, C++, or similar; strong analytical and communication skills; professional English; familiarity with application security concepts (OWASP/CWE) and secure coding. No AI-specific experience required; guidelines and verification criteria provided.