Senior Offensive Security Engineer — AI Frontier

Fluidstack; Greater London; On-site; GBP 167,000 - 205,000; Full time

Job summary

Fluidstack is seeking a seasoned security professional to lead red team and offensive security initiatives across modern data-center and cloud environments. You will emulate threat actors, test networks and applications, and break into multi-tenant systems to drive robust security improvements.

We value expertise in cloud platforms (AWS/GCP/Azure), Kubernetes, and CI/CD, plus hands-on coding in Python or Go to build custom tooling.

Qualifications

• Hands-on experience in red teaming and offensive security.
• Expertise in at least two areas: networks, OT/ICS, web/API apps, cloud, Kubernetes, CI/CD.
• Proven ability to find novel attack paths and chain vulnerabilities across boundaries.
• Experience running red team operations in well-defended environments.
• Experience finding authentication, authorization, and multi-tenant flaws in web apps and APIs.
• Proficiency in Python or Go and building tooling when off-the-shelf tools fall short.
• Experience using AI to speed up recon, vulnerability discovery, exploit development, or attack-path analysis.

Responsibilities

• Run red and purple team operations emulating advanced threat actors across our networks, data center OT, and applications.
• Pen test the networks behind our GPU clusters, from frontend and backend fabrics to out-of-band management and site connectivity.
• Test data center OT, including building management, power monitoring, cooling controls, in partnership with site operations.
• Break the customer-facing platform, including the console, public APIs, and identity and access controls.
• Assess internal and employee-built applications and the CI/CD pipelines that ship them.
• Partner with security and engineering on AI-specific attack scenarios and contribute to AI-assisted offensive testing tools.
• Present findings to technical and executive audiences as clear, actionable risk that shapes the security roadmap.

Skills

Red teaming

Offensive security

Cloud (AWS/GCP/Azure)

Kubernetes

CI/CD pipelines

Threat modeling

Python

Go

Job description

Fluidstack is seeking a seasoned security professional to lead red team and offensive security initiatives across modern data-center and cloud environments. You will emulate threat actors, test networks and applications, and break into multi-tenant systems to drive robust security improvements.

We value expertise in cloud platforms (AWS/GCP/Azure), Kubernetes, and CI/CD, plus hands-on coding in Python or Go to build custom tooling.