C1 Sr. Security Engineer at C1 builds security automation and tooling to integrate security into the development lifecycle. The role spans application, cloud security, and compliance with a focus on automation and risk-based approaches.
Responsibilities
We're hiring a Senior Security Engineer to join a small, early-stage security team with a broad remit - spanning security engineering, application and cloud security, and compliance. This is a generalist role: you'll have the opportunity to go deep in one domain over time while staying hands-on and supportive across others. Our stack is primarily Go and AWS.
Little of this job is manual. Instead of hand-reviewing every ticket, spec, or deploy, you'll spend your time building the purpose-built agents and skills that do that work continuously, and using them to orchestrate security into the development lifecycle through a risk-based approach. Our goal is to bake security into design specs up front, not catch it in post-deploy review.
You don't just want to hand engineering teams a list of findings - you want to roll up your sleeves and help implement the fix. You care about solving problems systemically, not just patching individual instances, and you want your work to make it easier for everyone at the company to build securely by default.
Define and drive security standards and secure-by-default solutions, serving as a subject matter expert for application and/or cloud security.
Build purpose-built agents and skills that orchestrate security into the development lifecycle through a risk-based approach, automating the manual, repetitive work (triage, enrichment, review) so the team can focus on judgment calls, not queues.
Shift security left by baking risk-based review into design specs and architecture decisions, rather than relying on post-deploy audits to catch issues.
Build security tooling and automation that scales security practices across engineering, and help implement meaningful, actionable security observability and detection signals.
Lead threat modeling and risk assessment for high-risk features and platform changes.
Assess and help mitigate security risks introduced by agentic development practices and AI-powered product features running in production.
Partner with engineering teams to prioritize and remediate critical threats, help define API security standards, and conduct security code reviews.
Continuously explore and adopt open-source tools to assess the security of and test our services, rather than defaulting to manual review.
Identify systemic security risks and lead multi-team remediation efforts end-to-end, not just the initial recommendation.
Qualification
Background in Software EngineeringHands-on code review experienceShow Us Your Agent WorkThis role expects realA projectExperience with KubernetesThis is a high-leverage role on a small
Required
Proven experience securing enterprise SaaS applications, including authentication flows, authorization patterns, and input validation at API boundaries.
Demonstrated experience securing deployment and change-management mechanisms for software and infrastructure.
Background in Software Engineering, Platform Engineering, Systems Engineering, Network Engineering, Cloud Security, or Application Security.
Hands-on code review experience, ideally in Go, Python, or Rust.
Experience with AWS (or another major cloud provider) and comfort working across cloud infrastructure.
Comfortable working both independently and collaboratively in a fast-paced, high-growth environment.
Curious and current on modern security practices, tooling, and emerging threats, including how AI is changing the threat landscape.
Someone to participate quarterly in-person in one of our primary offices San Francisco, or Portland Oregon.
Show Us Your Agent Work
This role expects real, hands-on experience building agents and automation for security, so we ask candidates to show it rather than just claim it. As part of the process, be ready to share one or more of the following:
A project, demo, or repo where you built an agent, skill, or automation that replaced manual security work (triage, review, detection, etc.).
Examples of how you use AI coding tools or agentic workflows in your day-to-day work.
Preferred
Experience with Kubernetes, service mesh, or PKI/network technologies (Consul, Envoy, Cilium, Vault, Istio, etc.).
Experience building or extending internal security tooling, automations, or agents.
Prior experience at a high-growth SaaS or identity/access management company.
This is a high-leverage role on a small, early-stage security team: your scope will be broad, your ownership will be real, and the systems you build will shape how a security-first company secures its own products and development lifecycle. You'll have the chance to specialize in the domain you care most about while still touching the full breadth of the security program.
