Job Title: Senior Engineer (Fraud) Company Name: Apollo.io Job Url: https://job-boards.greenhouse.io/apolloio/jobs/5799355004 Job Description: Back to jobs Senior Engineer (Fraud) Remote, Canada; Remote, United States 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. Your Role & Mission This role sits at the intersection of engineering, security, and fraud operations. The hired candidate will play a critical role in evolving Apollo’s abuse detection and account security capabilities. As a Senior Engineer (Fraud), you’ll work closely with Fraud Operations, Data Science, Application Security, and Product to modernize abuse detection logic. You'll prototype and deploy new risk decisioning systems and build the technical foundation for new fraud decision models over the next several quarters. This role is ideal for a senior engineer who thrives in ambiguous, data-driven problem spaces and enjoys building systems that protect our customers and business. Daily Adventures & Responsibilities Lead the implementation and ongoing improvement of abuse detection services and customer account security features With assistance of technical leadership, implement a home-grown risk decision engine Build and maintain APIs to support extensible, low-latency risk decisioning Research and analyze abuse tools and attacker tactics to inform detection strategies Participate in fraud incident triage and lead development of mitigations and remediation Collaborate with Data Science and Data Engineering on model feature and system design Work closely with Fraud Operations and Application Security to align detection and response Stay informed on fraud prevention trends and apply relevant insights internally Skills & Relevant Experience 5+ years building production backend systems in a SaaS or similar environment Experience designing scalable backend services; exposure to risk or decisioning systems a plus Proven track record of designing customer-first features Ability to explore and validate ideas using imperfect or partially structured data Strong foundation in secure system design and layered defenses Comfortable presenting designs to both technical peers and senior stakeholders Familiarity with common abuse vectors, evasion techniques, or scraping patterns Strong ownership mindset and ability to prioritize effectively Fraud, trust & safety, or security-adjacent experience preferred Clear written and spoken English communication Our tech stack is React/Redux/NodeJS on the frontend, Ruby/Ruby on Rails/MongoDB/Elasticsearch on the backend, and Kubernetes/Docker/Ansible/Terraform in infrastructure. Apollo.io Tech Blog: Deep dives into engineering, product design, and company-culture stories from the Apollo team, offering behind-the-scenes insight into how Apollo builds and scales its B2B sales platform. The listed Pay Range reflects the total cash compensation inclusive of annual base salary and annual bonus as applicable. For sales roles, the range provided is the role’s On Target Earnings ("OTE") range, meaning that the range includes both the sales commissions/sales bonus target and annual base salary for the role. This salary range may be inclusive of several career levels at Apollo and will be narrowed during the interview process based on a number of factors, including the candidate’s experience, qualifications, and location. Applicants interested in this role who are not located in the US may request the annual salary range for their location during the interview process. Additional benefits for this role may include: equity; company bonus or sales commissions/bonuses; 401(k) plan; at least 10 paid holidays per year, flex PTO, and parental leave; employee assistance program and wellbeing benefits; global travel coverage; life/AD&D/STD/LTD insurance; FSA/HSA and medical, dental, and vision benefits. Tier 1 Pay Range (San Francisco, New York City, Seattle) $154,900 - $212,960 USD Tier 2 Pay Range (All other US Locations) $154,900 - $212,960 USD 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 First Name* Last Name* Email* Phone Country* Phone* Resume/CV* Attach Enter manually Accepted file types: pdf, doc, docx, txt, rtf Education School Select... Degree Select... Discipline Select... Start date month Select... Start date year End date month Select... End date year Add another Are you legally authorized to work in the country/state/province where this position is located?* Select... Will you now or in the future require sponsorship or a work visa to continue employment in this location?* Select... LinkedIn Profile* What are your total salary expectations?* What is the name of a scaled production system or service you built or significantly contributed to? In 1–2 sentences, describe what it did, the scale it operated at and your specific role in building it.* Have you worked on security, abuse prevention, fraud detection, or risk-related features? If so, briefly describe the problem you were solving, your specific contribution, and the impact of the work.* Imagine you are reviewing every incoming request to a REST API and must decide whether to allow or deny it. What three signals or attributes would you evaluate to make that decision, and why would each one meaningfully improve your accuracy?* 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. Powered by Smart Key Available Click here or press Ctrl + Q to generate resume for your profile ×