About Fluidstack

We build and operate high-performance GPU clusters so the most ambitious teams can move fast, stay focused, and scale without friction. Our clusters power top AI labs, governments, and enterprises. Our customers include Mistral, Poolside, Black Forest Labs, Meta, and more.

Our team is highly motivated, and focused on providing a world class supercomputing experience. We put our customers first in everything we do, working hard to not just win the sale, but to win repeated business and customer referrals.

We hold ourselves and each other to high standards. We expect you to care deeply about the work you do, the products you build, and the experience our customers have in every interaction with us.

You must work hard, take ownership from inception to delivery, and approach every problem with an open mind and a positive attitude. We value effectiveness, competence, and a growth mindset.

About the Role

Fluidstack is looking for a seasoned Senior / Staff Network Security Engineer to spearhead our security strategy and defend our fast-growing cloud platform. You will design and deploy advanced safeguards concentrated on the network perimeter, ensuring our edge remains secure, resilient, and reliable at massive scale. Operating in a high-throughput environment, you'll keep our infrastructure and services protected while earning trust across the organization. The ideal hire brings +5 years of deep expertise in modern cloud and network architectures-and a passion for cultivating a security-first culture through mentorship and leadership.

Focus Perimeter & Edge Security Design: Architect and deploy resilient protections at the network edge -including perimeter firewalls, proxy layers, WAFs, and CDN-based controls-to shield Fluidstack's globally distributed footprint. Every ingress point and service should be hardened against unauthorized activity and attack vectors. DDoS Resilience: Create and maintain sophisticated DDoS-defense programs that preserve uptime. Continuously analyze traffic, fine-tune safeguards such as rate-limiting and traffic filtering, and react decisively to volumetric spikes or atypical patterns. Driving Zero-Trust: Lead the rollout of a Zero-Trust model across Fluidstack's cloud and network domains. Engineer solutions that enforce least-privilege, continuous verification, and service micro-segmentation, eliminating implicit trust at every tier. Monitoring & Incident Handling: Stand up comprehensive network-security monitoring to surface threats early. Detect indicators of compromise, hunt for vulnerabilities, and orchestrate rapid incident-response actions to limit blast radius. Cross-Team Partnership: Collaborate closely with Networking, Infrastructure, SRE/DevOps, and Software Engineering to embed security best practices into designs, deployments, and pipelines. Offer expert input during architecture and code reviews to guarantee security-by-design. Leadership & Mentoring: Champion security initiatives and cultivate a security-first culture. Coach junior engineers and peer teams on network-security fundamentals, deliver training, and model strict adherence to policies and standards. Policy Stewardship: Author, refine, and enforce security policies and SOPs suited to a highly scalable, distributed environment. Periodically reassess network and cloud-security posture, ensuring alignment with industry benchmarks as the company scales. About You Proven Experience: 5 + years in hands-on network-security engineering, protecting large-scale cloud or hyperscale environments and complex distributed systems. Edge-Security Mastery: Deep expertise in edge-protection technologies - DDoS mitigation, web-exploit defense, and Zero-Trust implementations. Cloud & Network Know-How: Strong conceptual and practical command of modern cloud and network security. Proficient in protocols (TCP/IP, DNS, BGP, HTTP/S), segmentation, VPNs, and firewall tuning; experienced securing AWS, GCP, Azure, or bespoke hyperscale and containerized platforms. Security Leadership: Demonstrated ability to own security programs end-to-end, mentor engineers, and instill a security-centric mindset across varied teams. Collaborative Communicator: Excellent at partnering with Networking, Infrastructure, DevOps/SRE, and Software groups to craft security solutions that protect critical assets while empowering the business. Policy & Compliance Expertise: Skilled in crafting and evaluating security controls for massively scalable systems, and familiar with frameworks such as NIST, ISO 27001, and SOC 2 in cloud contexts. Nice to haves Hyperscale Background: Experience inside a top-tier cloud provider or hyperscale setting (FAANG-class or similar) and familiarity with unique security challenges at extreme scale. DDoS/WAF Toolset: Acquainted with enterprise-grade DDoS and web-application-security platforms - Cloudflare, AWS Shield, Akamai, Arbor, F5, etc. - and adept at tuning WAF rules and traffic-scrubbing tactics. Zero-Trust & IAM: Hands-on design of Zero-Trust networks, including IAM, SSO, MFA, and NAC solutions. Automation & Scripting: Comfortable scripting or coding (Python, Go, etc.) to automate security workflows, integrate tools, and secure IaC and CI/CD pipelines. Certifications: Credentials such as CISSP, CCSP, GIAC (GSEC, GCIH, ...), or cloud-security specialties (AWS/Azure) that attest to a solid security foundation. Lifelong Learner: Active in the security community or open-source projects, with current knowledge of emerging threats, vulnerabilities, and defenses in network and cloud security. Benefits Competitive total compensation package (cash + equity). Retirement or pension plan, in line with local norms. Health, dental, and vision insurance. Generous PTO policy, in line with local norms.

Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans' status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law.