Senior Systems Engineer – Application Security

Cloudflare

. Design systems and write code following bleeding-edge industry best practices .

Posted 9/23/2026full-timePortugalSenior💰 $66,000 - $91,000 per yearWebsite

Core Competencies

Role fit

Core Competencies

Use this summary to align your resume positioning with the role.

Demonstrates expertise in software development with a focus on Go or Rust, alongside strong Linux/Unix fundamentals and experience in deploying distributed systems at scale. Emphasizes a commitment to best practices in coding, security awareness, and collaborative knowledge sharing within engineering teams.

Highest-signal resume keywords

Go ProgrammingRust ProgrammingKubernetesDistributed SystemsLinux/Unix Fundamentals

ATS Keywords

Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills

Software DevelopmentCode ReviewSecurity Risk AssessmentDevOps ToolingSystem Design

Soft Skills

EmpathyEmotional IntelligenceTeam CollaborationResponsibilityPersistent Attitude

Tools & Technologies

KubernetesSaltKafkaSystemd

Industry Keywords

Cyber SecurityBest PracticesOn-Call SupportSoftware DeploymentRFC Review

Tech Stack

Tools & technologies

Cyber SecurityDistributed SystemsKafkaKubernetesLinuxRustSaltStackUnixGo

About the role

Key responsibilities & impact

Design systems and write code following bleeding-edge industry best practices
Help other team members follow best practices
Review RFCs, technical specifications and code
Deploy and maintain live software-based services at scale, up to 100m requests per second and 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
Provide input on how security risks impact Cloudflare’s products
Work with Engineers and Product Managers outside the immediate team to communicate the roadmap and get things done

Requirements

What you’ll need

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 such as Kubernetes, Salt, Kafka or Systemd
Strong Linux / Unix fundamentals
Experience working with distributed systems at scale
Experience with cyber security preferred but not essential
Persistent, can-do attitude
Genuine willingness to assume good faith in others
Empathetic and emotionally intelligent
Willingness to take responsibility for the culture and environment created around you
Ability to obtain authorization to receive software or technology controlled under U.S. export laws without sponsorship for an export license, if applicable

Benefits

Comp & perks

Unlimited leave policy
Equity program with stock grants on joining and regular refreshers linked to performance
Medical insurance
Dental insurance
Mental health support
Tax efficient defined contributions pension plan
Life insurance