Principal Engineer, Cloudflare

• Our ideal candidate has deep technical expertise in distributed systems architecture and an equally deep understanding of how threat actors operate — their tactics, techniques, procedures, and infrastructure
• You think like an attacker and build like an engineer who has been burned by production incidents at 3 AM
• You are energized by hard problems, impatient with the status quo, and have a track record of shipping solutions that others said couldn't be done
• 15+ years of cyber security experience with an emphasis on building systems to present adversarial trends and techniques both as an internal reputational service and a product facing analyst service
• 10+ years of experience building and operating large-scale distributed systems in production, with demonstrated expertise in complex system architecture and design
• Deep, hands-on proficiency in Go and/or TypeScript, with production experience deploying services in Kubernetes and on edge computing platforms (e.g., Cloudflare Workers, D1/SQLite-at-the-edge)
• Subject matter expertise in threat intelligence, adversarial analysis, or detection engineering — you understand the Cyber Kill Chain, know how to track TTPs, and can reason about attacker infrastructure at scale
• Proven ability to work across organizational boundaries and lead technical initiatives that span multiple teams, codebases, and problem domains simultaneously
• Experience with AI-assisted development and agentic AI workflows
• Strong architectural judgment — you know when to build, when to refactor, and when to burn it down and start over
• Experience designing and operating critical data pipelines (Kafka, Temporal, or similar) and working with SQL databases (PostgreSQL) and caching layers (Redis) at scale
• Excellent communication skills — you can explain a complex system design to a VP and debug a race condition with a junior engineer in the same afternoon
• A track record as a disruptor: you have examples of fundamentally improving how a team, system, or organization operates, not just shipping features

Desirable

• Cloudforce One is Cloudflare's threat operations and research team, responsible for identifying and disrupting cyber threats ranging from sophisticated cyber criminal activity to nation-state sponsored advanced persistent threats (APTs)
• Cloudforce One works in close partnership with external organizations and internal Cloudflare teams, continuously developing operational tradecraft and expanding ever-growing sources of threat intelligence to enable expedited threat hunting and remediation
• Members of Cloudforce One are at the helm of leveraging an incredibly vast and varied set of data points that only one of the world's largest global networks can provide
• The team is able to analyze these unique data points, at massive scale and efficiency, synthesizing findings into actionable threat intelligence to better protect our customers
• Cloudflare's Trust & Safety team is the frontline defense against platform abuse — phishing, malware distribution, fraud, and content that undermines the safety of the internet. Together, these teams form a unified capability: from tracking an adversary's infrastructure to dismantling it at network scale
• Cloudflare is a system spanning the globe, on a mission to make the internet better, safer, and more powerful every day
• We are looking for a Principal Engineer who is equal parts architect, threat analyst, and disruptor — someone who doesn't just build systems but fundamentally rethinks how we detect, analyze, and neutralize threats across one of the world's largest networks
• This is not a role that lives in a single team or a single codebase. You will operate across the full breadth of Cloudflare Products, diving into whatever problem is most critical — whether that's redesigning a detection pipeline in Kubernetes, deploying a new mitigation capability at the edge via Workers, building agentic AI workflows that automate analyst tradecraft, or architecting a data system that processes trillions of signals per day
• You will be the person teams turn to when the problem is ambiguous, the architecture is complex, and the adversary is sophisticated
• Drive architectural direction and technical strategy across Cloudforce One engineering, spanning services that run in Kubernetes, on the edge (Workers, D1), and across Cloudflare's global network
• Identify and dismantle technical bottlenecks, legacy patterns, and architectural debt that slow down threat detection and abuse response — then replace them with systems that are faster, more reliable, and more elegant
• Design and build critical data pipelines and services to collect, enrich, analyze, and expose threat intelligence and abuse signals at massive scale, helping identify Tactics, Techniques, and Procedures (TTPs) and Indicators of Compromise (IOCs)
• Serve as a technical force multiplier across multiple concurrent projects — you will context-switch between threat intelligence platforms, abuse detection systems, legal response tooling, and customer-facing security products as priorities demand
• Bring a threat-informed perspective to engineering decisions: understand how adversaries adapt, how detection rules degrade, and how to build systems that stay ahead of evolving attack techniques
• Collaborate with Threat Intelligence researchers, Trust & Safety analysts, Product, Legal, and other engineering teams to translate complex security and compliance requirements into scalable, production-grade solutions
• Mentor and elevate the engineering talent around you — set the bar for code quality, system design, operational rigor, and security-first thinking across both organizations
• Develop and champion agentic AI workflows and AI-assisted development practices that accelerate threat hunting, detection engineering, and abuse investigation
• Own the operational excellence of the systems you touch, including participation in on-call rotations and incident response

• 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