Senior Security Engineer, Infrastructure Security

At Click Up, we're building the future of work: the first truly converged AI workspace unifying tasks, docs, chat, calendar, and enterprise search, all supercharged by context-driven AI. We are an AI-native company. Every team member is expected to leverage AI daily, and we evaluate AI fluency as part of our hiring process. Join us and help redefine what's possible.

Security at Click Up is engineering-focused. We partner with teams across the company to protect our platform, our internal systems and our customers through secure design, defensive controls, detection and response. We build tooling and automation, including AI-powered workflows, to turn what we learn into lasting improvements.

Infrastructure Security at Click Up secures the cloud, compute, network and access layers underneath Click Up: a multi-account AWS organization, a large Kubernetes fleet, infrastructure managed as code and the identity systems engineers use to reach production. We are a small team that works agentic first, using AI agents we build and maintain ourselves to multiply what a team our size can cover.

You will support this mission by thinking like a developer, breaking down a problem that we face, testing a method to approach it with automation, and implementing solutions that yield compounding value. Your skills to uncover threat indicators will be the foundation of this work.

• Architecture, proposals and reviews. Act as an initial reviewer on infrastructure proposals and designs from engineering and non-engineering teams such as business systems and go-to-market. Write our own security proposals and review the changes that follow. Translate security requirements and agent findings into clear guidance for less-technical partners, and bring their needs back into our designs.
• Agentic security tooling and agent infrastructure. Build, evaluate and maintain the agents behind our reviews, triage and investigations, and help run the sandboxed, observable infrastructure they operate on.
• Detection, investigation and response. Lead cloud and infrastructure alerts and incidents through to resolution and root cause, working alongside App Sec and incident response on incidents that span both.
• Identity, access and least privilege. Move people, CI and services toward least privilege and just-in-time access across our cloud organization and the tooling engineers use to reach production. Deliver fixes as secure building blocks that teams adopt by default.
• Compute, network and pipeline security. Harden our container, serverless and virtual machine workloads, our network perimeter and our CI/CD pipelines, and add checks so each class of issue is caught automatically next time.
• Continuous review and audit evidence. Move vulnerability, access and attack-surface reviews from point-in-time checks to continuous monitoring that also produces evidence for our infrastructure controls.

• 5+ years in security engineering, cloud infrastructure or SRE, with at least 2 years securing AWS at organization scale.
• At least a year of agentic development experience: building agent skills and tools for real engineering work, and developing and maintaining the development harness they run in, from configuration and permissions to integrations, evaluations and cost controls. You can secure agents against prompt injection, over-privileged tools and unaudited actions, and explain how agents fall into the confused deputy problem and the lethal trifecta.
  
  You validate agent output against evidence and decide where human review is required.
• Deep AWS IAM experience: IAM Identity Center or an equivalent SSO model, SCPs, permission boundaries, resource and key policies, cross-account trust, and the ability to prove a policy's effect with simulation rather than inference.
• Production Kubernetes security on EKS or similar, covering RBAC, workload identity, network policy, admission control and container runtime hardening.
• AWS networking for security: VPC design, endpoints and endpoint policies, network and DNS firewalls, egress control, and WAF.
• Fluency with infrastructure as code such as Terraform, including reusable patterns, multi-environment rollouts and reading plans for security impact.
• Experience with CNAPP, SIEM or runtime security tooling and the cloud detection sources around it, such as Cloud Trail, Guard Duty and Access Analyzer.
• Experience investigating cloud and infrastructure security events: correlating cloud audit, Kubernetes,…