AI Engineer (Node.js)

TL;DR

Senior AI Engineer (Node.js): Shaping AI infrastructure and driving production-ready LLM experiences with an accent on advanced prompt systems, structured outputs, and complex LLM workflows. Focus on observability, debugging, evaluation, and data-driven decisions for continuous model quality improvement.

Location: Remote. Must be located within approximately ± 4 hours of CET. Applicants from any country are welcome to apply, including Ukraine, Serbia, Czech Republic, Slovakia, Montenegro, Moldova, Georgia, Kazakhstan, Lithuania, Latvia, Brazil, Turkey, South Africa, Poland, Estonia, Cyprus, Malta, Israel.

Company

hirify.global is a leading tech company that creates and operates innovative consumer products across the health, education, and entertainment industries.

What you will do

• Design and implement advanced prompt systems with dynamic templates and structured outputs.
• Build and maintain robust evaluation pipelines using Langfuse for real-time feedback and quality scoring.
• Debug complex LLM chains to optimize cost, latency, and context window usage.
• Conduct AI A/B testing and make data-driven deployment decisions for new models and prompts.
• Develop scoring systems to analyze AI output quality and identify root causes of errors.
• Continuously re-evaluate model performance and fine-tune models to meet specific domain requirements.

Requirements

• Deep knowledge of Node.js and Next.js for building reliable services.
• Proven experience in dynamic prompting, context injection, and variable handling.
• Experience with unified APIs like OpenRouter, including rate limits and model selection.
• Understanding of LLM observability principles (tracing, test datasets, scoring systems) with Langfuse or similar.
• Experience with evaluation methodologies (RAGAS or LLM-as-a-judge systems).
• Analytical and iterative mindset for continuous product improvement.

Nice to have

• Practical experience in fine-tuning models for specific domain tasks or JSON compliance.
• Understanding of RAG architecture, including indexing, retrieval, and re-ranking.
• Basic Python knowledge for working with data science scripts or AI evaluation libraries.

Culture & Benefits

• Remote work environment with flexible hours and unlimited PTO.
• Paid national holidays and a company-provided MacBook.
• Flexible Independent Contractor Agreement offering autonomy and entrepreneurial opportunities.
• Opportunity for personal and professional growth in a fast-growing team.

Hiring process

• Application review (typically 3 to 5 days).
• Recruiter Screening (40 minutes).
• Technical Interview (60 minutes) followed by a Final Interview (30 minutes).