Principal Machine Learning Engineer
Core
Building AI Context systems that help HubSpot's AI understand customer, company, activity, and workflow data across the CRM platform to transform complex data into customer value.
Role type
Principal Machine Learning Engineer (Applied AI)
Builds
Production ML systems for AI context, including model training, inference, experimentation, and feedback loops for customer-facing products.
Domain
SaaS / Marketing & CRM / Applied Machine Learning
Deliverable
production ML models
Required skills
Deep learning, optimization, regression, transformers, large language models, transfer learning, retrieval, ranking, recommendations, classification, NLP, personalization, architecture design, data governance, privacy, bias mitigation, scalable system design, feature engineering, model evaluation
Preferred skills
Experience with messy/heterogeneous data, leading ambiguous 0-to-1 projects, mentoring senior engineers, pragmatic decision-making on ML vs rules vs product changes
Technologies
scikit-learn, PyTorch, TensorFlow, modern model-serving and evaluation systems
Responsibilities
Define technical direction for applied ML and AI systems; develop, evaluate, and productionize models for ambiguous problems; mentor and coach engineers; architect solutions for AI context problems; expand analysis beyond offline/online metrics to include reliability, cost, and data governance.
Seniority
Principal, hands-on IC with strategic leadership
