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Senior Systems Engineer - Application Security

Cloudflare· Engineering
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Hybrid (Lisbon), Hybrid (London)Full-timePosted 4w ago

About the role

Senior Systems Engineer focused on application security at Cloudflare, blending software development with security at internet scale. Hybrid role with in-person requirements in Lisbon, Portugal or London, UK.

Responsibilities

  • Design systems and write code following bleeding edge industry best practices and help others on the team do the same. Review RFCs, technical specifications and code.
  • Deploy and maintain live software-based services at scale (up to 100m requests / second, 1m customers). Take regular shifts as part of the team’s On Call rota.
  • Support and grow other Engineers through knowledge sharing.
  • Keep up to date with trends in detecting current and emerging security risks to web applications and provide input on how these impact Cloudflare’s products.
  • Work with Engineers and Product Managers outside your immediate team in communicating our roadmap and getting things done.

Qualifications

  • At least 5 years of professional experience working hands-on as a software developer.
  • Proficiency with at least one of Go or Rust.
  • Exposure to devops tooling like Kubernetes, Salt, Kafka or Systemd.
  • Strong Linux / Unix fundamentals.
  • Experience working with distributed systems at scale.
  • Experience with cyber security is preferred but not essential.

Skills

Required:Go or RustDevOps toolingLinux/Unix fundamentalsDistributed systems

Benefits

  • Unlimited leave policy
  • Competitive base salary
  • Equity program with stock grants on joining and regular refreshers linked to performance
  • Medical and dental insurance
  • Mental health support
  • Tax efficient defined contributions pension plan
  • Life insurance
Last updated Oct 7, 2026. Interested? Apply on the company site.

About Cloudflare

Connect, protect, and build everywhere | Cloudflare

Make employees, applications and networks faster and more secure everywhere, while reducing complexity and cost.

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