Data Engineer (LLM Data & Prompt Engineering)

TL;DR

Data Engineer (AI/LLM): Designing and evaluating complex prompts for Large Language Models to refine high-quality datasets for AI training workflows with an accent on prompt engineering principles and data shaping. Focus on ensuring model outputs align with customer expectations and validating accuracy and relevance of AI responses.

Location: US / North America. This opportunity is only available for candidates located in the United States.

Compensation: $100/hour

Company

hirify.global, operating as Welo Data, partners with technology companies to provide high-quality, ethically sourced datasets and AI training services, leveraging over 25 years of experience.

What you will do

• Design complex LLM prompts that accurately represent real customer journeys and service interactions.
• Partner with Field Engineers to transform raw data into structured, high-quality tasks for model training.
• Annotate and review tasks to ensure strict quality standards and alignment with expected customer outcomes.
• Validate and assess model responses to ensure accuracy, relevance, and confidence in outputs.

Requirements

• Language: Native or professional fluency (C1/C2) in English.
• Location: Must be based in the United States or North America.
• Understanding of LLM behavior and prompt engineering principles.
• Strong attention to detail, critical thinking, and comfort working with ambiguous scenarios.
• Proficiency in SQL for data extraction, Python (Pandas, NumPy) for data manipulation, and experience with annotation tools (e.g., Labelbox, Prodigy).
• Advanced proficiency in Google Sheets/Drive and familiarity with version control tools (GitHub).
• Experience working with playground environments and prompt debugging.
• Excellent technical writing skills and ability to clearly explain data requirements.

Nice to have

• Prior experience in data labeling, technical support analysis, or AI model evaluation.
• Background or exposure to AI-related projects.

Culture & Benefits

• Work with cutting-edge AI models and experienced engineering teams.
• Opportunity to make a direct impact on model quality and performance.
• Project-based freelance work with flexible schedule options (minimum 4 hours/day Monday to Friday OR 2 hours Monday–Friday plus 10 hours over the weekend).
• Reliable and consistent availability is mandatory.
• Start date: Monday, December 22nd. Only candidates able to start on this date will be considered.