System Engineer, Behavioral Analysis

About Us 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. 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. Available Locations: Austin, TX, New York, NY, Seattle, WA About the Role Cloudflare One brings together secure access, network connectivity, and data protection. Our products generate massive amounts of signals about how people and agents access applications, use the network, and handle data—but a security practitioner needs more than isolated events. They need to understand what happened, whether it is unusual, why it matters, and what to investigate next. The UEBA (User and Entity Behavior Analytics) team builds the systems behind those answers. We ingest and evaluate Cloudflare One signals, produce high fidelity user-risk events, maintain risk scores, and make that information available to customer-facing experiences and other Cloudflare services. Today, we are focused on expanding our behavioral detections and improving the clarity of the resulting investigations and integrations. As a Systems Engineer, you will build and operate production services in this pipeline. You might implement a detection for an unusual pattern of DNS activity or data movement, improve how events contribute to a user’s risk score, or make risk-event history easier for customers to investigate. You will own well-defined projects through design, implementation, testing, rollout, and operational follow-through, working with other engineers, Product, and partner teams across Cloudflare. Responsibilities • Build behavioral detections. Turn product requirements and available telemetry into production-ready detections across signals such as Access, Gateway, DNS, device posture, and data protection. Define the data dependencies, evaluation approach, and how you will assess signal quality before release. • Make risk understandable. Help connect detection output to event history, logs, and customer-facing investigations so practitioners can see what triggered a finding and how a user’s risk changed. • Design & Scale Infrastructure: Architect, deploy, and maintain robust distributed systems, focusing on high availability, low latency, and horizontal scalability. • Collaborate across teams. Collaborate with Product and engineers in Access, Gateway, Analytics and Reporting, Logs, and other data-producing or data-consuming teams to agree on event contracts and deliver end-to-end functionality. • Ensure Reliability. Participate in architecture reviews, capacity planning, and proactive system health monitoring to guarantee maximum uptime and resilience. Desirable Skills, Knowledge, and Experience • 3+ years of professional experience building, testing, and operating backend or distributed systems in production. • Strong proficiency in at least one systems programming language (e.g., Go, Rust, C/C++) with a track record of writing clean, maintainable code. • 3+ years of practical experience with databases and data-intensive services—for example, PostgreSQL, ClickHouse, or comparable relational or analytical stores. • Experience reasoning about event-driven systems: message delivery, duplicate or late events, state, failure recovery, and safe changes to live consumers or APIs. • Clear written and verbal communication, and an ability to work through technical decisions with product and engineering partners. • Experience using metrics, logs, traces, profiling, and experiments to understand production behavior and validate improvements • Bring strong opinions, clear judgment, and a willingness to revise your view when data, users, or production reality prove otherwise. Bonus Points • Experience with security analytics, fraud or abuse detection, identity, Zero Trust, SASE, or network telemetry. • Familiarity with Kafka or other streaming systems; Kubernetes; and high-volume event processing. • Experience with statistical baselines, anomaly detection, time-windowed aggregation, or evaluating false positives and detection coverage. • Familiarity with DNS, HTTP, authentication events, data-loss-prevention signals, or endpoint-security integrations. • Experience with distributed state, caches, object storage, or safe migration of a legacy production service. Compensation Compensation may be adjusted depending on work location and level. New York and Seattle Estimated Base salary $150,000 - $206,000. Austin Texas Estimated Base salary $136,000 - $187,000. 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. This position may require access to information protected under U.S. export control laws, including the U.S. Export Administration Regulations. Please note that any offer of employment may be conditioned on your authorization to receive software or technology controlled under these U.S. export laws without sponsorship for an export license. Cloudflare is proud to be an equal opportunity employer. We are committed to providing equal employment opportunity for all people and place great value in both diversity and inclusiveness. All qualified applicants will be considered for employment without regard to their, or any other person's, perceived or actual race, color, religion, sex, gender, gender identity, gender expression, sexual orientation, national origin, ancestry, citizenship, age, physical or mental disability, medical condition, family care status, or any other basis protected by law. We are an AA/Veterans/Disabled Employer. Cloudflare provides reasonable accommodations to qualified individuals with disabilities. Please tell us if you require a reasonable accommodation to apply for a job. Examples of reasonable accommodations include, but are not limited to, changing the application process, providing documents in an alternate format, using a sign language interpreter, or using specialized equipment. If you require a reasonable accommodation to apply for a job, please contact us via e-mail at hr@cloudflare.com or via mail at 101 Townsend St. San Francisco, CA 94107.