Cyber Security Jobs

• London
• Hybrid
• Mid-level

Builds new features and systems for Cloudflare's edge web server, focusing on the rules engine and its control plane. Works in Rust and Go on large-scale distributed systems, performance engineering, and reliability across a platform handling over 100 million HTTP requests per second.

Rust · Go · Cloudflare

• London
• Mid-level

Builds and maintains a Chromium-based browser engine, remote rendering and streaming tech, and distributed services that run browser sessions across a global network. Day-to-day work spans C++ browser code, Go/Rust/TypeScript services, debugging across browser processes and Linux hosts, and improving latency and reliability, with production on-call.

Chromium · Cloudflare Workers · Nomad +3

• London
• Senior

Builds and operates Cloudflare's Chromium-based browser isolation engine, working across C++, Rust, Go and TypeScript on remote rendering, streaming and distributed session services. The role spans systems programming, distributed systems and security, leading multi-component initiatives and on-call incident response.

Chromium · Cloudflare Workers · Nomad +3

• London
• Lead

Owns product strategy, roadmap and commercial model for a new publicly trusted certificate authority, spanning ACME issuance, certificate lifecycle automation, revocation and Certificate Transparency. Works across engineering, compliance, legal and go-to-market on high-consequence infrastructure, with an ACME-first, automation-first and post-quantum-ready design.

AWS Certificate Manager · AWS Private CA · Google Trust Services +7

• London
• Mid-level

Acts as primary technical responder for premium enterprise customers, autonomously investigating complex threat telemetry and handling live incident response for volumetric DDoS and application-layer attacks. Implements mitigation across OSI Layers 3, 4 and 7 using Cloudflare's security suite, performs packet and traffic flow analysis, and advises customers during active incidents. Requires 24x7 rotating shifts.

Cloudflare · Magic Transit · Magic Firewall +7

• London
• US$215,000 – US$225,000 pa
• Lead

Lead research, design and evaluation of detection models identifying automated, fraudulent and malicious activity across Internet-scale traffic. Own the detection measurement framework for noisy or delayed ground truth, mentor others, and drive cross-functional detection strategy with ML, data and product teams.

Python · SQL