Senior AI Engineer (Node.js/Next.js)

TL;DR

Senior AI Engineer (Node.js/Next.js): Building and optimizing AI infrastructure and LLM workflows with an accent on prompt engineering, structured outputs, and observability. Focus on improving model quality, reducing latency, and establishing quantitative evaluation pipelines.

Location: Remote (Must be located within ± 4 hours of CET time zone)

Company

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

What you will do

• Design complex, dynamic prompt templates with conditional logic to maximize reasoning and generation quality.
• Implement structured response schemas (JSON mode, Zod) to ensure predictable integration into application logic.
• Build robust evaluation pipelines and real-time scoring systems using Langfuse.
• Perform deep debugging of LLM chains and conduct A/B testing across models via OpenRouter.
• Drive key AI features from early experimentation through to production deployment.
• Develop scoring systems to identify root causes of hallucinations and logic errors.

Requirements

• Deep knowledge of Node.js, Next.js, and TypeScript.
• Proven experience building prompts dependent on complex input variables and context injection.
• Experience with LLM observability tools like Langfuse (tracing, test datasets, scoring).
• Experience with evaluation frameworks like RAGAS or custom "LLM-as-a-judge" systems.
• Fluency in Russian and/or Ukrainian.
• Must be based within ± 4 hours of the CET time zone.

Nice to have

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

Culture & Benefits

• Remote work environment promoting a healthy work-life balance.
• Unlimited paid time off (PTO) and paid national holidays.
• Company-provided MacBook for all employees.
• Flexible independent contractor agreements offering tax advantages and autonomy.

Hiring process

• Recruiter Screening (40 minutes).
• Technical Interview (60 minutes).
• Final Interview (30 minutes).