Posted Aug 19, 2026

SQL Query Evaluation Specialist

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About OpenTrain OpenTrain is the #1 platform for building careers in AI training and data labeling. We help specialists find and manage AI training work, build a unified portfolio, and grow a durable freelance career doing the technical work they already know how to do best. Why AI training matters AI training is the human side of building modern machine intelligence: people create, review, and correct examples so models learn to behave. This work is often 100% remote, flexible, and accessible to technical experts who want recurring contract work shaping how AI systems reason about data. The role You will evaluate AI-generated SQL, database designs, and data-processing logic; identify correctness, performance, and methodological issues; and produce high-quality reference solutions and explanations that help improve model outputs. • Position: Remote contractor (part-time, 20+ hours/week). • Pay: $50 USD per hour. • Work includes rating, comparing, and writing reference answers for AI responses to SQL and database problems. What you'll do • Review AI-generated SQL queries, schemas, and ETL/ELT logic for correctness and clarity. • Analyze query plans, joins, window functions, and aggregation for correctness and performance. • Identify issues with indexing strategies, concurrency, locking, and schema design. • Fact-check data-related claims and validate results against expected behavior or sample data. • Write detailed, step-by-step reference solutions and explanations that show reasoning and trade-offs. • Rate and compare multiple AI responses for correctness, completeness, and methodological soundness. • Contribute database engineering expertise to annotation guidelines and training examples. Requirements You must meet the technical requirements below to be considered. We will preserve these criteria when reviewing applications. • Expert-level SQL, including complex joins, window functions, aggregation, and query plan analysis. • Experience with database performance tuning, indexing strategies, and concurrency/locking issues. • Hands-on experience with relational data models, schemas, and data warehouse structures. • Strong ETL or ELT experience and familiarity with cloud or on-prem data platforms. • Comfort with version control, CI/CD practices, and collaborative database workflows. • Clear written and spoken English and the ability to explain technical reasoning precisely. • Bachelor's degree or higher in a related technical field. Helpful background • Experience designing star and snowflake schemas. • Familiarity with migrations, backup/recovery planning, and monitoring. • Methodical approach to finding subtle data, logic, or query issues. • Prior experience evaluating AI-generated technical content or participating in AI data training is a strong plus. Schedule, location, and application details This is an hourly, remote contractor role; you will be paid per hour at the listed rate. The role expects 20+ hours per week and is open to qualified contractors in approved countries (see list below). English is required for written and spoken communication. • Hourly rate: $50 USD per hour (PAY_PER_HOUR). • Minimum time commitment: 20+ hours/week. • Languages: English required. • Approved countries: BD, BT, BR, KH, DE, IN, ID, MY, NP, PK, SG, LK, TH, PH, US, TL, VN. • Employment types: Contractor, Part-time.