Senior Data Scientist, Detection

At Cloudflare, we’re not looking for people who wait for a polished roadmap; we’re looking for the builders who see the cracks in the Internet that everyone else has simply learned to live with. We value candidates who have the instinct to spot a “normalized” problem and the AI-native curiosity to create a solution using the latest tools. Our culture is built on iteration, leveraging AI to ship faster today to make it better tomorrow, while ensuring that every improvement, no matter how small, is shared across the team to lift everyone up. If you’re the type of person who values curiosity over bureaucracy, and that AI is a partner in solving tough problems to keep the Internet moving forward, you’ll fit right in., Cloudflare’s Engineering Team is home to some of the industry’s top engineers, dedicated to building and scaling innovative software that handles a huge proportion of the Internet. Our Detection department sits at the heart of that mission: we identify automated, fraudulent, and malicious activity across the Internet and through our gateway. We develop advanced detection systems and machine learning models that operate at scale, collaborating with Product and Engineering teams across the company to protect our customers and stay ahead of the constantly evolving threat landscape., * Research, design, and evaluate detection models that identify automated, fraudulent, and malicious activity across Internet-scale data.

• Dig into massive datasets to uncover the patterns and behaviors that distinguish adversaries from legitimate users.
• Define how detection success is measured, designing metrics and evaluation strategies for problems where ground truth is noisy, delayed, or contested.
• Stay current on emerging AI/ML research and evaluate how new techniques (e.g., LLMs, generative AI) can be applied to our products.
• Partner with ML Engineers, Data Engineers, and Product to take detection approaches from research to production and measure their real-world impact.

• Fraud and bots at scale. You have experience across fraud, abuse, and/or bot detection on large, high-velocity traffic. You may focus on one, but you transfer instincts between them.
• Strong fundamentals, fluent in data. You have solid applied statistics, machine learning, and AI methodology fundamentals. You choose the right technique for the problem, and are fluent with large-scale data.
• You have at least 5-7 years of experience professionally working in Data Science, ML Engineering, or Software Engineering.
• You are very comfortable with Python & SQL in production environments., * At home in ground truth ambiguity. Building detections when ground truth is scarce is the heart of this job. You make real progress with weak, delayed, or absent labels and you’re energized by adversaries that fight back.
• You don’t burn signals. You understand (or are curious to learn) how to act on detections without tipping your hand, knowing that how you deploy and respond can erode your future visibility.
• Pragmatic about complexity. You know when a simple solution beats a complex one, and you don’t chase small gains at disproportionate cost.
• Disciplined in code. You apply strong programming and engineering best practices in both research and production code.
• Impact-driven and clear. You connect your work to business impact and communicate clearly across technical and non-technical stakeholders.

Pulled from the full job description

• 401(k)
• Health insurance
• Paid time off
• Vision insurance
• Dental insurance
• Flexible spending account
• Bereavement leave, Compensation may be adjusted depending on work location.
• For New York City based hires: Estimated annual salary of $185,000 - $231,000., Cloudflare offers a complete package of benefits and programs to support you and your family. Our benefits programs can help you pay health care expenses, support caregiving, build capital for the future and make life a little easier and fun! The below is a description of our benefits for employees in the United States, and benefits may vary for employees based outside the U.S.

Health & Welfare Benefits

• Medical/Rx Insurance
• Dental Insurance
• Vision Insurance
• Flexible Spending Accounts
• Commuter Spending Accounts
• Fertility & Family Forming Benefits
• On-demand mental health support and Employee Assistance Program
• Global Travel Medical Insurance

Financial Benefits

• Short and Long Term Disability Insurance
• Life & Accident Insurance
• 401(k) Retirement Savings Plan
• Employee Stock Participation Plan

Time Off

• Flexible paid time off covering vacation and sick leave
• Leave programs, including parental, pregnancy health, medical, and bereavement leave

At Cloudflare, we are on a mission to help build a better Internet. Today the company runs one of the world’s largest networks that powers millions of websites and other Internet properties for customers ranging from individual bloggers to SMBs to Fortune 500 companies. Cloudflare protects and accelerates any Internet application online without adding hardware, installing software, or changing a line of code. Internet properties powered by Cloudflare all have web traffic routed through its intelligent global network, which gets smarter with every request. As a result, they see significant improvement in performance and a decrease in spam and other attacks. Cloudflare was named to Entrepreneur Magazine’s Top Company Cultures list and ranked among the World’s Most Innovative Companies by Fast Company., What Makes Cloudflare Special?

We’re not just a highly ambitious, large-scale technology company. We’re a highly ambitious, large-scale technology company with a soul. Fundamental to our mission to help build a better Internet is protecting the free and open Internet.

Project Galileo: Since 2014, we’ve equipped more than 2,400 journalism and civil society organizations in 111 countries with powerful tools to defend themselves against attacks that would otherwise censor their work, technology already used by Cloudflare’s enterprise customers-at no cost.

Athenian Project: In 2017, we created the Athenian Project to ensure that state and local governments have the highest level of protection and reliability for free, so that their constituents have access to election information and voter registration. Since the project, we’ve provided services to more than 425 local government election websites in 33 states.

1.1.1.1: We released 1.1.1.1 to help fix the foundation of the Internet by building a faster, more secure and privacy-centric public DNS resolver. This is available publicly for everyone to use - it is the first consumer-focused service Cloudflare has ever released. Here’s the deal - we don’t store client IP addresses never, ever. We will continue to abide by our privacy commitment and ensure that no user data is sold to advertisers or used to target consumers.

Sound like something you’d like to be a part of? We’d love to hear from you!

Please note that applicants who progress to the offer stage of the interview process may be asked to attend an in-person interview within one of the Cloudflare Offices or Cloudflare Hubs. More details about this will be available at that stage of the interview process.