Jobs Private USA → Technology → Data, analytics and AI → Principal Machine Learning Engineer

Principal Machine Learning Engineer

ZoomInfo Technologies LLC · Waltham, MA · posted 42 days ago

In short: Principal Machine Learning Engineer at ZoomInfo Technologies LLC in Waltham, MA, posted 42 days ago.

By AtiveSite · Published 07/11/2026 · Updated 09/11/2026 · Every figure is linked to its source below.

ZoomInfo Technologies LLCemployer

Waltham, MAlocation

Data, analytics and AIsub-niche

42 days agoposted

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The job

LIVE Employer public job feed (private-sector employer) Source: the employer's public careers feed · Data: listed 2026-09-28

Employer	ZoomInfo Technologies LLC
Location	Waltham, Massachusetts
Field	Technology › Data, analytics and AI
Level	not stated
Source category	867 Engineering - Data Science
Posted	2026-09-28 (42 days ago)
Work arrangement	On-site at the location listed
Pay	Not published in the source listing

Job description

ZoomInfo is where careers accelerate. We move fast, think boldly, and empower you to do the best work of your life. You’ll be surrounded by teammates who care deeply, challenge each other, and celebrate wins. With tools that amplify your impact and a culture that backs your ambition, you won’t just contribute. You’ll make things happen fast.

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 problems. You'll decide when classical machine learning, statistics, or language models is the right tool, and turn good judgment into standards other teams adopt.

What You'll Do

You will set technical strategy for the data graph, entity resolution, buying intent, and agent context, deciding which problems to take on, in what order, and how the pieces connect.
You will frame and ship problems nobody has framed yet, such as extraction for companies with no public footprint or semantic intent at web scale, deciding what not to build as deliberately as what to build.
You will define evaluation standards that other teams adopt, including sampling methodology, human labels, validated LLM judges, and release gates, and know where each one breaks.
You will define the data contracts between the data graph, intent signals, and the agents that consume them, including agent memory, keeping the system cost-effective to run across the full dataset.
You will turn good choices into defaults across the group: the baseline every model must beat, how uncertainty is reported, and which metrics get retired when they mislead.
You will lead design reviews, mentor senior engineers, shape hiring, and represent the team's technical judgment to product and leadership.

What You Bring

Must-Have:

You have set technical direction as an individual contributor for a problem area spanning more than one team, with the resulting machine learning systems in production and owned after launch — depth of impact matters more than years or past titles.
You bring breadth across classical machine learning on large, messy tabular data, applied statistics, language processing at scale, and LLM agents or multi-step systems, with recognized depth in at least one.
You have defined and driven adoption of evaluation standards beyond your own team for systems with no single right answer, including LLM judges validated against human labels and results reported with their limits.
You have a track record of changing how a group builds or measures — for example, introducing a baseline or review practice that other teams now use.
You have made cost and capacity decisions for model training and serving, including when to self-host, distill, or call a hosted model, with cost tracked per unit of work.
You are hands-on in production Python and strong SQL with distributed data processing experience, and you use AI coding tools daily with rigorous review of their output.

Preferred:

You have experience with ranking and retrieval, including embeddings, learned re-ranking, and metrics such as recall@k, MRR, and nDCG.
You bring entity resolution, knowledge graph, or web-scale information extraction experience on messy, real-world data.
You have trained and served open-weight models in PyTorch or an equivalent framework, including GPU capacity planning.
You have built user memory or context systems for agents, or defended LLM systems against adversarial inputs and prompt injection.

#LI-Remote

#LI-VC1

Actual compensation offered will be based on factors such as the candidate’s work location, qualifications, skills, experience and/or training. Your recruiter can share more information about the specific salary range for your desired work location during the hiring process. We want our employees and their families to thrive.

In addition to comprehensive benefits we offer holistic mind, body and lifestyle programs designed for overall well-being. Learn more about ZoomInfo benefits here.

Below is the US base salary for this position. Additional compensation such as Bonus, Commission, Equity and other benefits may also apply.$192,500—$302,500 USD

About us:

ZoomInfo (NASDAQ: GTM), the all-in-one AI GTM platform, enables sales, marketing, and customer success teams to execute their go-to-market strategy with confidence. Powered by the industry's most comprehensive B2B data, including more than 100 million companies, 500 million contacts, and billions of signals, ZoomInfo delivers the intelligence, automation, and integrations that modern revenue teams need to identify, engage, and convert their best buyers.

ZoomInfo is committed to protecting your privacy when you apply for jobs with us. Please review our Job Applicant Privacy Notice for more details on how we handle your personal information.

ZoomInfo may use a software-based assessment as part of the recruitment process. More information about this tool, including the results of the most recent bias audit, is available here.

ZoomInfo is proud to be an equal opportunity employer, hiring based on qualifications, merit, and business needs, and does not discriminate based on protected status. We welcome all applicants and are committed to providing equal employment opportunities regardless of sex, race, age, color, national origin, sexual orientation, gender identity, marital status, disability status, religion, protected military or veteran status, medical condition, or any other characteristic protected by applicable law. We also consider qualified candidates with criminal histories in accordance with legal requirements.

For Massachusetts Applicants: It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability. ZoomInfo does not administer lie detector tests to applicants in any location.

Explore around this job

Field: Technology Sub-niche: Data, analytics and AI All jobs at ZoomInfo Technologies LLC Jobs in Massachusetts Jobs in Waltham, MA Waltham city guide Massachusetts state guide Middlesex County economy

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About the role

This is a — role in the Technology field (Data, analytics and AI) at ZoomInfo Technologies LLC.

We could not match this job title to one occupation in the official wage statistics, so no pay estimate is shown. Pay is not in the source listing; ask the employer for the range and compare in the 240 job niches.

Does the pay work here? (estimate)

Gross salary a year Filing State income tax rate %

Estimate for a wage earner: 2026 federal brackets and standard deduction (IRS), Social Security 6.2% up to $184,500, Medicare 1.45% (+0.9% above $200,000 single / $250,000 married), and a state rate you set; set your own state tax rate. It ignores credits, pre-tax deductions, local taxes and benefits. Sources: IRS: tax year 2026 inflation adjustments · SSA wage base per Federal Register notice 2025-19763.

How to prepare and behave

This is editorial guidance, not information from the employer.

Read the whole description and match your examples to its requirements; use the same words the posting uses where they are true for you.
Research the employer before the interview: what it does, who its customers are and recent news; prepare two or three questions about the work.
Arrive early (or log in early for a video call), dress one step above the daily dress code, and test your camera and audio beforehand.
Answer with short stories: the situation, what you did and the result. Give numbers when you have them and never invent them.
Be honest about gaps; say what you did to learn and how fast you can close them.
Ask about the team, the first 90 days, how success is measured and the schedule; do not open with salary and time off.
When pay comes up, know the market range for the occupation and your lowest acceptable offer before you answer; ask for the full package in writing.
Send a short thank-you message within a day, mentioning one thing you discussed.
Have code, data work or projects you can show, and be ready to think aloud: many technical interviews test how you reason, not only the answer.

Know your rights as a candidate and an employee:

The city

The job is in Waltham, MA. Below is what the official statistics say about living and working there.

How Waltham compares. Among the 80 largest places in Massachusetts, Waltham is #17 by population, #14 for long commutes (#1 = fewest), #66 for rent (#1 = cheapest), #60 for homeownership (#1 = highest). Its county, Middlesex County, is #2 of 14 counties for average pay ($113,704).

The place in numbers

Waltham has 64,902 residents (ACS 2020–2024), about 0.9% of the population of Massachusetts. It covers 13 square miles of land, which works out to roughly 5,092 people per square mile. The median age is 34.4, 14% younger than the state median (34.4 against 40.0).

Housing

The median gross rent is $2,268 a month (rent plus utilities), 29% above the state median ($2,268 against $1,762). Over a year that is 22.6% of the median household income. US housing guidance treats housing as affordable when it takes 30% of income or less, so the typical household is under that line. The median home value is $748,700, which is 6.2 times the median household income ($120,216); a ratio above 5 usually means buying is out of reach without savings or a second income. 49.7% of households own their home, 21% below the state average (49.7% against 62.5%). A low ownership share points to a rental-heavy market with more apartments and shorter stays.

Work and pay

The Boston-Cambridge-Newton, MA-NH metropolitan area has 2,703,890 jobs in the BLS wage survey, and the median pay across all occupations is $66,620 a year, 31% above the national median ($66,620 against $50,980). The biggest occupation groups are office and administrative support (265,830 jobs, median $56,580); management (254,700 jobs, median $166,580); business and financial operations (242,960 jobs, median $102,660). The area is most specialised in life, physical, and social science (2.6 times) and architecture and engineering (1.4 times), where the share of workers is well above the national share. The best-paying groups with at least 5,000 jobs are management ($166,580) and legal ($135,160). In 2026M09 the unemployment rate of Middlesex County was 3.8%. 68.4% of residents aged 16 and over are in the labour force. The city lies in Middlesex County; its jobs, pay by industry and GDP are on the county page.

Getting around

Among workers, 53.0% drive alone, 4.5% use public transit, 6.2% walk, 24.2% work from home. 13.8% of workers commute 45 minutes or more, 36% below the state average (13.8% against 21.5%). Remote work is more common than in the state as a whole, which widens the set of employers a resident can work for without moving.

People and education

57.3% of adults aged 25 and over hold a bachelor's degree or higher, 21% above the state share (57.3% against 47.3%). 26.3% of residents were born outside the United States, 46% above the state share (26.3% against 18.1%). The poverty rate is 9.4%, 6% below the state rate (9.4% against 10.0%).

Climate

The warmest month is Jul, averaging 72°F (22.4°C), and the coolest is Jan at 26°F (-3.5°C). About 1,206 mm (47 inches) of precipitation falls in a year; Oct is the wettest month (123 mm) and Jan the driest (80 mm). These values come from NASA satellite-based climatology on a grid of about 50 km, so they describe the wider area, not a weather station in the city.

Nearby cities to compare

Closest cities in this guide: Belmont (3 miles, rent 11% higher); Lexington (4 miles, rent 27% higher); Newton (4 miles, rent 4% higher); Arlington (4 miles, rent 8% lower). Rent differences are against Waltham; use the Compare tab to put any two cities side by side.

Full guide to Waltham →Massachusetts guide All jobs in Waltham

Official links for Waltham

These links go to official sources and open in a new window. The first one is the government's or company's own site as listed in Wikidata (property "official website"); check it before relying on it.

Where to live

CITY Official statistics Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year (via Census Reporter) · Data: ACS 2020–2024

Places within 50 miles (straight line) of Waltham, MA that have a guide, with what living there costs. No pay estimate is shown because the title did not match one occupation.

Sort:

Place ⇅	Distance from the job city ⇅	Median rent ⇅	Median home value ⇅	Median household income ⇅	Commute 45+ min ⇅	Rent as % of occupation pay ⇅	Open jobs there ⇅
Waltham, MA	0 mi	$2,268	$748,700	$120,216	13.8%	n/a	Jobs
Belmont, MA	3 mi	$2,527	$1,159,000	$183,137	19.2%	n/a	—
Lexington, MA	4 mi	$2,891	$1,203,100	$238,444	27.7%	n/a	—
Newton, MA	4 mi	$2,370	$1,264,900	$190,304	17.0%	n/a	—
Arlington, MA	4 mi	$2,082	$933,800	$150,701	27.3%	n/a	—
Wellesley, MA	6 mi	$2,886	$1,582,700	$250,001	23.5%	n/a	—
Cambridge, MA	6 mi	$2,787	$1,092,100	$130,748	13.3%	n/a	Jobs
Winchester, MA	7 mi	$2,279	$1,215,200	$230,198	25.5%	n/a	—
Brookline, MA	7 mi	$2,835	$1,246,800	$142,101	14.7%	n/a	—
Medford, MA	7 mi	$2,509	$755,500	$129,540	22.0%	n/a	—
Somerville, MA	7 mi	$2,517	$911,300	$132,572	20.9%	n/a	Jobs
Needham, MA	7 mi	$2,409	$1,188,500	$214,308	21.6%	n/a	Jobs
Burlington, MA	8 mi	$2,718	$740,600	$146,436	16.3%	n/a	—
Woburn, MA	8 mi	$2,221	$673,500	$111,185	17.2%	n/a	—
Stoneham, MA	9 mi	$2,035	$671,900	$113,964	22.9%	n/a	—
Everett, MA	10 mi	$2,076	$610,000	$85,218	31.6%	n/a	—
Malden, MA	10 mi	$2,204	$633,500	$100,606	30.2%	n/a	—
Dedham, MA	10 mi	$2,042	$661,800	$128,955	21.4%	n/a	—
Melrose, MA	10 mi	$1,970	$822,900	$133,953	34.0%	n/a	—
Chelsea, MA	11 mi	$1,956	$493,500	$72,179	28.1%	n/a	—

Career paths

We could not match this title to one occupation, so here are the other sub-niches in Technology, where your skills may carry over:

Cybersecurity (713) Software engineering (4089) Cloud, IT and infrastructure (1040) Product management (836)

Distances

CITY Calculation (straight line) Source: U.S. Census Bureau Gazetteer (coordinates) · Data: 2024

How far Waltham, MA is from the 20 largest US cities, in straight-line miles (not driving distance). Click a column to sort.

Sort:

From ⇅	Straight-line distance (miles) ⇅	Population of that city ⇅
New York, NY	184 mi	8,483,844
Philadelphia, PA	261 mi	1,579,706
Columbus, OH	632 mi	914,802
Charlotte, NC	715 mi	903,844
Indianapolis, IN	796 mi	885,860
Chicago, IL	842 mi	2,711,226
Jacksonville, FL	1,013 mi	977,670
Oklahoma City, OK	1,484 mi	697,125
Dallas, TX	1,539 mi	1,307,930
Fort Worth, TX	1,568 mi	963,194
Houston, TX	1,596 mi	2,328,253
Austin, TX	1,685 mi	979,539
Denver, CO	1,750 mi	718,877
San Antonio, TX	1,757 mi	1,479,835
Phoenix, AZ	2,283 mi	1,642,323
Seattle, WA	2,477 mi	754,195
San Diego, CA	2,565 mi	1,389,526
Los Angeles, CA	2,591 mi	3,857,263
San Jose, CA	2,666 mi	990,138
San Francisco, CA	2,715 mi	830,235

Nearby cities with open jobs (within 120 miles)

Sort:

City ⇅	Straight-line distance ⇅	Open jobs ⇅
Cambridge, MA	6 mi	109
Framingham, MA	11 mi	6
Boston, MA	12 mi	1,034
Andover, MA	19 mi	8
Barrington, RI	45 mi	1
Amherst, MA	65 mi	14

The employer

ZoomInfo Technologies LLC is the employer in this listing. See all its open jobs here →

We do not hold headcount or revenue for this employer. Check its careers site and, if it is listed on a stock exchange, its public filings (SEC EDGAR search).

What it is like to work at a company (culture, schedules, benefits) is not in the source data, so we do not describe it. Read the description and ask the questions under "How to prepare".

Other open jobs at ZoomInfo Technologies LLC

Senior GTM Consultant

ZoomInfo Technologies LLC · Waltham, MA · Other roles · posted 3 days ago

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FAQ

What is the Principal Machine Learning Engineer job at ZoomInfo Technologies LLC?

A private-sector role in technology (data, analytics and ai) listed 42 days ago. The full description is on this page and on the employer's page.

Where is this job?

Waltham, MA.

How do I apply?

Use the "View this job and apply on the employer's page" button. AtiveSite does not receive applications.

How much does it pay?

The listing does not publish pay, and we could not match the title to one official occupation.

What is the cost of living there?

Median rent in Waltham is $2,268 a month and median household income $120,216 (ACS 2020–2024).

How old is this listing?

It was posted on 2026-09-28 (42 days ago). Jobs older than 90 days are not shown.

Are there similar jobs?

Yes: browse data, analytics and ai jobs in Massachusetts.

Sources and terms

Job data: ZoomInfo Technologies LLC careers page public feed (listing dated 2026-09-28). The job disappears from this site when it disappears from the source.
Wages and projections: BLS OEWS (May 2025) and Employment Projections 2025–35.
City and county figures: Census Bureau ACS 2020–2024, BEA, BLS QCEW and LAUS, NASA POWER climatology; distances from Census Gazetteer coordinates.

AtiveSite is not affiliated with or endorsed by the employer or any government agency, and does not process applications. Verify every detail with the employer before acting.

Sources

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