Browser Security Engineer: Harden Chromium in Kernel microVMs

usekernel; San Francisco (CA); On-site; USD 180,000 - 260,000; Full time

Benefits offered by this job

Relocation assistance

Daily lunches on us

Unlimited PTO

401k + company match

Premium medical + dental coverage

Equity above market

Job summary

Kernel is 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.

Responsibilities include debugging, patching, and optimizing Chromium builds within Kernel’s microVM environments, implementing network isolation and IP handling, and collaborating on kernel security policies.

Qualifications

• Experience with Chromium internals, browser sandboxes, or renderer/network stacks.
• Experience with Linux kernel, microVMs (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).

Responsibilities

• Debug, patch, and optimize Chromium builds running inside Kernel’s microVM 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.

Skills

Chromium internals

Browser sandboxing

Low-level debugging

Networking basics

Security engineering

Tools

Linux kernel

microVMs

gVisor

strace

gdb

Job description

Kernel is 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.

Responsibilities include debugging, patching, and optimizing Chromium builds within Kernel’s microVM environments, implementing network isolation and IP handling, and collaborating on kernel security policies.