Staff Security Engineer at Zencoder · LumiJobs

Responsibilities

We’re looking for a hands-on Senior or Staff Security Engineer to lead and own security across the company.
Part of the job is the work every company needs and too few do well: hardened cloud infrastructure, least-privilege access, secure delivery, vulnerability management, penetration testing, and incident response. The threats in this space are increasing exponentially. The other part is an evolving domain with no playbook. Our product runs agents that read untrusted content, execute code, and hold credentials. Attackers now use AI to probe and fuzz faster than before. Prompt injection, data exfiltration through allowed channels, cross-session access, and insecure agent-written code reaching production are real risks for us today, not research topics.
We want someone who will help us close the obvious gaps without being asked, and finds the problems nobody has written down yet.
You'll work closely with our ITOps, platform and product engineers. Teams own their services and platform owns the monorepo pipeline. Your job is to improve our security posture without slowing delivery: build automated controls into existing workflows rather than rely on slow, blocking manual AppSec reviews. You'll test whether those controls hold, address critical risks, and take responsibility for security outcomes, not just recommendations.
This is a hands-on role - you'll be in the code, infra, and pipelines yourself.
Set security priorities and drive fixes through to verified completion;
Find application vulnerabilities through code review, penetration testing and agent-specific red-team exercises;
Work with ITOps, platform and product engineers to harden infrastructure and build security into delivery pipelines;
Build detection for user and agent activity, and lead incident response.
Essential Qualifications
Strong application security background - you can spot exploitable flaws, and explain the fix;
Hands-on penetration testing and offensive security experience across web applications, APIs, and cloud infrastructure;

Staff Security Engineer

Responsibilities

Qualification

Required

Preferred

Benefits

Company

Zencoder

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