Staff Machine Learning Engineer

Back to jobs New Staff Machine Learning Engineer Remote, India Apply Apollo.io is the leading go-to-market solution for revenue teams, trusted by over 500,000 companies and millions of users globally, from rapidly growing startups to some of the world's largest enterprises. Founded in 2015, the company is one of the fastest growing companies in SaaS, raising approximately $250 million to date and valued at $1.6 billion. Apollo.io provides sales and marketing teams with easy access to verified contact data for over 210 million B2B contacts and 35 million companies worldwide, along with tools to engage and convert these contacts in one unified platform. By helping revenue professionals find the most accurate contact information and automating the outreach process, Apollo.io turns prospects into customers. Apollo raised a series D in 2023 and is backed by top-tier investors, including Sequoia Capital, Bain Capital Ventures, and more, and counts the former President and COO of Hubspot, JD Sherman, among its board members. About Apollo Apollo.io is the leading go-to-market platform for revenue teams, trusted by over 500,000 companies and millions of users globally. We provide sales and marketing teams with easy access to verified contact data for over 210 million B2B contacts and 35 million companies—plus the tools to engage and convert them all in one place. As an AI-native company , we are redefining how businesses drive pipeline and revenue. Backed by top-tier investors like Sequoia Capital and Bain Capital Ventures, and recently valued at $1.6B, Apollo is one of the fastest-growing SaaS companies in the world. Your Role & Mission We are looking for a Staff Machine Learning Engineer to join our growing Intelligence team. You will lead mission-critical initiatives that power ML-driven user experiences across search, recommendations, content generation, scoring, and more. Your role is to push Apollo forward as an AI-native product , helping us create intelligent, personalized, and highly automated features that scale. You will collaborate closely with engineers, product managers, and data scientists to build machine learning systems that enhance Apollo’s ability to guide our users to value—and drive the future of our AI platform. Responsibilities: Design, build, evaluate, deploy and iterate on scalable Machine Learning systems Drive end-to-end ML initiatives—problem definition, data exploration, modeling, productionization, and monitoring. Understand the Machine Learning stack at Apollo and continuously improve it Lead development of intelligent features powered by LLMs, embeddings, ranking models, and semantic search. Guide platform architecture decisions and contribute to foundational ML infrastructure (e.g., feature stores, MLOps). Work cross-functionally to define AI-first product experiences and rapidly iterate toward user impact. Mentor and uplevel engineers across the org, influencing engineering best practices and technical direction. Champion the use of AI internally to drive engineering and operational efficiency. Required Qualifications:  8+ years of experience building and scaling machine learning systems in production environments. Strong experience with LLMs and embeddings (e.g., fine-tuning, prompt engineering, vector databases). Hands-on experience with Python and modern ML libraries such as PyTorch, TensorFlow, HuggingFace, or Scikit-learn. Experience with cloud infrastructure (e.g., GCP), orchestration (Airflow), and experimentation platforms (e.g., mlflow, Databricks). Excellent collaboration and communication skills—can influence across product and engineering teams. Proven impact shipping ML-driven features in B2B SaaS products or enterprise platforms. Preferred Qualifications: Bachelors, Masters, or a PhD in Computer Science, Mathematics, Statistics, or other quantitative fields or related work experience Experience with retrieval-augmented generation (RAG), search infrastructure, or recommendations at scale. Exposure to GTM, marketing tech, or sales enablement domains in a B2B setting. We are AI Native Apollo.io is an AI-native company built on a culture of continuous improvement. We’re on the front lines of driving productivity for our customers—and we expect the same mindset from our team. If you're energized by finding smarter, faster ways to get things done using AI and automation, you'll thrive here. Why You’ll Love Working at Apollo At Apollo, we’re driven by a shared mission: to help our customers unlock their full revenue potential. That’s why we take extreme ownership of our work, move with focus and urgency , and learn voraciously to stay ahead. We invest deeply in your growth, ensuring you have the resources, support, and autonomy to  own your role and make a real impact . Collaboration is at our core—we’re all for one , meaning you’ll have a team across departments ready to help you succeed. We encourage bold ideas and courageous action , giving you the freedom to experiment, take smart risks, and drive big wins. If you’re looking for a place where your work matters, where you can push boundaries, and where your career can thrive—Apollo is the place for you.  Learn more  here! Create a Job Alert Interested in building your career at Apollo.io? Get future opportunities sent straight to your email. Create alert Apply for this job * indicates a required field Autofill with Greenhouse First Name * Last Name * Email * Phone * Resume/CV * Attach Attach Dropbox Google Drive Enter manually Enter manually Accepted file types: pdf, doc, docx, txt, rtf LinkedIn Profile What is your total years of experience? * Select... How many years of relevant experience do you have as a Machine Learning engineer? * Select... Can you briefly describe your hands-on experience with LLMs and embedding, including any work on fine-tuning, prompt engineering, or using vector databases? * How do you evaluate ML model performance? Which metrics do you prioritize? * What is your Current CTC (Fixed + variable components + Stocks)? * What is your Expected CTC? * Are you serving notice period? * Select... What is your notice period? * Immediate Joiner 15 Days 30 Days 45 Days 60 Days 90 Days Voluntary Self-Identification For government reporting purposes, we ask candidates to respond to the below self-identification survey. Completion of the form is entirely voluntary. Whatever your decision, it will not be considered in the hiring process or thereafter. Any information that you do provide will be recorded and maintained in a confidential file. As set forth in Apollo.io’s Equal Employment Opportunity policy, we do not discriminate on the basis of any protected group status under any applicable law. Gender Select... Are you Hispanic/Latino? Select... Race & Ethnicity Definitions If you believe you belong to any of the categories of protected veterans listed below, please indicate by making the appropriate selection. As a government contractor subject to the Vietnam Era Veterans Readjustment Assistance Act (VEVRAA), we request this information in order to measure the effectiveness of the outreach and positive recruitment efforts we undertake pursuant to VEVRAA. Classification of protected categories is as follows: A "disabled veteran" is one of the following: a veteran of the U.S. military, ground, naval or air service who is entitled to compensation (or who but for the receipt of military retired pay would be entitled to compensation) under laws administered by the Secretary of Veterans Affairs; or a person who was discharged or released from active duty because of a service-connected disability. A "recently separated veteran" means any veteran during the three-year period beginning on the date of such veteran's discharge or release from active duty in the U.S. military, ground, naval, or air service. An "active duty wartime or campaign badge veteran" means a veteran who served on active duty in the U.S. military, ground, naval or air service during a war, or in a campaign or expedition for which a campaign badge has been authorized under the laws administered by the Department of Defense. An "Armed forces service medal veteran" means a veteran who, while serving on active duty in the U.S. military, ground, naval or air service, participated in a United States military operation for which an Armed Forces service medal was awarded pursuant to Executive Order 12985. Veteran Status Select... Voluntary Self-Identification of Disability Form CC-305 Page 1 of 1 OMB Control Number 1250-0005 Expires 04/30/2026 Why are you being asked to complete this form? We are a federal contractor or subcontractor. The law requires us to provide equal employment opportunity to qualified people with disabilities. We have a goal of having at least 7% of our workers as people with disabilities. The law says we must measure our progress towards this goal. To do this, we must ask applicants and employees if they have a disability or have ever had one. People can become disabled, so we need to ask this question at least every five years. Completing this form is voluntary, and we hope that you will choose to do so. Your answer is confidential. No one who makes hiring decisions will see it. Your decision to complete the form and your answer will not harm you in any way. If you want to learn more about the law or this form, visit the U.S. Department of Labor’s Office of Federal Contract Compliance Programs (OFCCP) website at www.dol.gov/ofccp . How do you know if you have a disability? A disability is a condition that substantially limits one or more of your “major life activities.” If you have or have ever had such a condition, you are a person with a disability. Disabilities include, but are not limited to: Alcohol or other substance use disorder (not currently using drugs illegally) Autoimmune disorder, for example, lupus, fibromyalgia, rheumatoid arthritis, HIV/AIDS Blind or low vision Cancer (past or present) Cardiovascular or heart disease Celiac disease Cerebral palsy Deaf or serious difficulty hearing Diabetes Disfigurement, for example, disfigurement caused by burns, wounds, accidents, or congenital disorders Epilepsy or other seizure disorder Gastrointestinal disorders, for example, Crohn's Disease, irritable bowel syndrome Intellectual or developmental disability Mental health conditions, for example, depression, bipolar disorder, anxiety disorder, schizophrenia, PTSD Missing limbs or partially missing limbs Mobility impairment, benefiting from the use of a wheelchair, scooter, walker, leg brace(s) and/or other supports Nervous system condition, for example, migraine headaches, Parkinson’s disease, multiple sclerosis (MS) Neurodivergence, for example, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, dyslexia, dyspraxia, other learning disabilities Partial or complete paralysis (any cause) Pulmonary or respiratory conditions, for example, tuberculosis, asthma, emphysema Short stature (dwarfism) Traumatic brain injury Disability Status Select... PUBLIC BURDEN STATEMENT: According to the Paperwork Reduction Act of 1995 no persons are required to respond to a collection of information unless such collection displays a valid OMB control number. This survey should take about 5 minutes to complete. Submit application