Browser Security Engineer

About Kernel

We’re building the developer platform that lets AI agents use applications, starting with browsers. Our edge is an infrastructure platform that’s extensible, observable, and built for scale from day one. Our platform handles the hard stuff: spinning up browsers quickly and efficiently at scale, providing great observability into their activity, and enabling both humans and AI agents to interact with them.

If you’re interested in building critical infrastructure for the next generation of AI applications, we’d love to chat.

We’re hiring a Browser Security Engineer to harden and extend our Chromium-based browser runtime. You’ll work at the intersection of sandboxing, networking, and virtualization — ensuring our browsers run securely and efficiently across thousands of concurrent users.

Debug, patch, and optimize Chromium builds running inside Kernel’s micro

VM environments.

• Implement and maintain network isolation, proxy routing, and IP handling for browsers.
• Collaborate with infra engineers on unikernel-based isolation, process scheduling, and kernel security policies.
• Build internal tooling for binary analysis, crash triage, and vulnerability monitoring.
• Support the team in maintaining secure supply chain and reproducible builds for our browser images.

• Deep familiarity with Chromium internals, browser sandboxes, or renderer/network stacks.
• Experience with Linux kernel, micro
  
  VMs (Firecracker, Cloud-Hypervisor, Kata, gVisor, etc.), or container isolation.
• Strong debugging skills with strace, gdb, perf, or similar low-level tools.
• Knowledge of networking fundamentals (DNS, TCP/IP, NAT, proxies, TLS).
• Background in security engineering or browser hardening a plus.

• Industry-competitive salary
• Above market equity
• Premium medical + dental coverage + dependent coverage
• Small, trusting team of senior + staff engineers
• Default async with minimal bureaucracy, only one meeting a week
• $1k / mo budget for LLM usage fees #vibecheck
• Daily lunches on us
• Unlimited PTO
• 401k + company match
• Relocation assistance

We have a simple process focused on real world collaboration and jointly getting to know each other: