Principal Machine Learning Engineer at ZoomInfo (Waltham)

ZoomInfo is a go-to-market platform that combines B2B data with marketing and sales AI. You'll set the technical direction for the intelligence layer every ZoomInfo AI agent reasons over — what's true about companies and the people in them, how they relate, and what they're buying. As a senior individual contributor with no direct reports, you will own strategy across the data graph, entity resolution, and buying intent, staying hands-on in the hardest of these pr

Key responsibilities

• Set technical strategy for the data graph, entity resolution, buying intent, and agent context, deciding which problems to take on, in what order
• Frame and ship problems nobody has framed yet, such as extraction for companies with no public footprint or semantic intent at web scale
• Define evaluation standards that other teams adopt, including sampling methodology, human labels, validated LLM judges, and release gates
• Define the data contracts between the data graph, intent signals, and the agents that consume them, including agent memory
• Turn good choices into defaults across the group: the baseline every model must beat, how uncertainty is reported
• Lead design reviews, mentor senior engineers, shape hiring, and represent the team's technical judgment to product and leadership

Requirements

• Set technical direction as an individual contributor for a problem area spanning more than one team
• Breadth across classical machine learning on large, messy tabular data, applied statistics, language processing at scale
• Defined and driven adoption of evaluation standards beyond your own team for systems with no single right answer
• A track record of changing how a group builds or measures — for example, introducing a baseline or review practice that other teams now use
• Made cost and capacity decisions for model training and serving, including when to self-host, distill, or call a hosted model
• Hands-on in production Python and strong SQL with distributed data processing experience

Location and schedule

• Onsite in Waltham, Massachusetts

Salary and benefits

US base salary $192,500 to $302,500 a year. ZoomInfo also offers benefits; the full list is on the posting.

How to apply

Apply on the company's own site.