Principal Machine Learning Engineer (AI)

Location: Sunnyvale, California, United States

Salary: $268,600–$395,000 USD per year, plus potential equity grants.

Company

hirify.global operates a delivery marketplace and develops advertising and promotional products connecting merchants with consumer demand.

What you will do

• Set the long-term technical direction for AI-first ads and promotions delivery systems.
• Design and build ranking, relevance, personalization, query understanding, and representation-learning models.
• Apply sequence modeling, deep learning, and large language models to real-time marketplace decisioning.
• Own the full machine learning lifecycle from data analysis and model development through production deployment, monitoring, and iteration.
• Design offline evaluations, online experiments, and metrics to measure quality, business impact, and tradeoffs.
• Collaborate with engineering, product, analytics, operations, data science, and design teams.

Requirements

• 5+ years of experience building, deploying, and scaling machine learning or AI models for large-scale, user-facing or data-intensive products.
• Deep expertise in deep learning, large language models, information retrieval, ranking and relevance, recommendation systems, natural language processing, or content understanding.
• Strong programming skills in Python, Java, or C++, with hands-on experience using PyTorch, TensorFlow, or XGBoost.
• Experience with data analysis, feature engineering, iterative model development, rigorous offline and online evaluation, monitoring, and improvement.
• Experience using AI coding tools such as Claude Code, Codex, or Cursor throughout the software development lifecycle.
• Bachelor’s, master’s, or doctoral degree in computer science, engineering, or a related field, or equivalent practical experience.

Nice to have

• Experience deploying LLM-based systems, prompt engineering, retrieval-augmented generation, or generative recommendation systems.
• Experience with large-scale personalization, user modeling, retrieval, ranking, and relevance.
• Open-source contributions, publications, or applied research in machine learning, NLP, information retrieval, or related fields.

Culture & Benefits

• Cross-functional collaboration across engineering, analytics, product, and operations.
• 401(k) plan with employer matching.
• Medical, dental, vision, disability, and basic life insurance.
• 16 weeks of paid parental leave, family-forming assistance, wellness benefits, and mental health support.
• Flexible paid time off and 80 hours of paid sick time per year for salaried roles.
• Paid holidays, commuter benefits match, and other employee benefits.