Senior Security Engineer: Cloud Defense & Scale

XOXO AI Inc.; San Francisco (CA); On-site; USD 250,000 - 500,000; Full time

Benefits offered by this job

Health, dental, vision benefits

Equity between 1% and 5%

Job summary

XOXO AI Inc. is seeking a seasoned Security Engineer in San Francisco, CA to protect our systems and maintain user trust. You will harden our cloud foundations, enforce network boundaries, and build tooling for rapid remediation as we scale.

You’ll partner with founders and engineering to define security as a core principle, embedding security into the development lifecycle and driving cross-team risk reduction through pragmatic guardrails.

Qualifications

• Shipped security or infrastructure systems from design to production with measurable improvements in risk, reliability, or incident outcomes.
• Expert knowledge of cloud hardening, including configuration baselines, network topology, and policy enforcement.
• Strong generalist software engineering background and ability to review production code for security risks.
• Hands-on experience securing web apps and APIs, especially auth flows, access control, secrets management, input validation, and data protection.
• Built segmentation/isolation strategies that reduce blast radius and prevent lateral movement.

Responsibilities

• Partner with engineering, product, and research to embed security into the development lifecycle (threat modeling, design reviews, secure defaults).
• Harden cloud infrastructure and enforce network topology standards (subnets, firewalls, routing) and org security policies.
• Implement isolation and segmentation strategies that limit blast radius and prevent lateral movement.
• Build and maintain security tooling and automation for engineers (CI/CD checks, scanning, guardrails) and drive findings to remediation.
• Improve observability, detection, and incident response for security-relevant events (intrusions, abuse patterns, DDoS, and bots) including rapid containment.
• Design and manage identity and access management (humans + services) and third-party integration controls, prioritizing private connectivity and least privilege.

Skills

Threat modeling

Cloud hardening

IAM/Access control

Security tooling

Tools

CI/CD security

Web apps security

Job description

XOXO AI Inc. is seeking a seasoned Security Engineer in San Francisco, CA to protect our systems and maintain user trust. You will harden our cloud foundations, enforce network boundaries, and build tooling for rapid remediation as we scale.

You’ll partner with founders and engineering to define security as a core principle, embedding security into the development lifecycle and driving cross-team risk reduction through pragmatic guardrails.