Senior Security Software Engineer, v0

v0 turns natural language into working, deployed applications. An agent writes code, executes it, and ships it on a user's behalf. That makes v0 one of the most interesting and highest-stakes security surfaces at Vercel: sandboxed code execution, multi-tenant isolation, permission boundaries between what a user asked for and what the agent actually did, and resistance to prompt injection and tool misuse.

We're looking for a Senior (IC4) software engineer with a strong security background to sit fully embedded inside the v0 team, not as a rotating auditor who reviews designs and files tickets, but as a peer engineer who owns security end to end for everything v0 ships. That means finding and fixing vulnerabilities yourself, building security features directly into the product, reviewing every new feature and launch before it goes out, and running the relationship with our HackerOne researcher community for anything v0-related. You'll spend real time being a great generalist engineer: building features, fixing bugs, shipping to production alongside the rest of the team. The difference is that you bring security judgment and hands-on ownership to everything the team builds, and you're the one who catches the sandbox escape, the auth gap, or the injection vector before it ships, rather than after.

This role reports into the security organization but is deployed full-time with v0, and is evaluated as much on shipped product velocity as on security outcomes. As a senior (IC4) engineer, you're expected to operate independently, set the security bar for the team, and be trusted to make the final call on v0-specific tradeoffs.

You're a software engineer first: 5+ years building and shipping production web applications, at a level where you operate independently (IC4/Senior). You can pick up a normal feature ticket and ship it end to end, this is not a pure audit/review role.

Strong full-stack fundamentals: Comfortable in TypeScript, React, and Node, and able to work in the same codebase, PR flow, and velocity as the rest of the v0 team.

Real security judgment: You understand authN/authZ design, sandboxing and isolation, injection vulnerability classes, and can reason about "an AI agent writing and running code" as a novel attack surface, even if your background so far has been primarily software engineering rather than a security title.

You influence through code, not just process: You'd rather fix the root cause in a PR than write a policy doc about it. You can be the security conscience of a fast-moving team without becoming its bottleneck.

Comfortable with ambiguity: v0's threat model is still being written. You're excited to define it rather than inherit a mature playbook.

Willing to build with v0, not just secure it: You're happy to actually go use v0 to build things and understand how our products work end to end, not just read the code from the outside.

Already a v0 user or familiar with how it and Vercel's broader product line work.

Hands-on experience with sandboxing, container isolation, or multi-tenant systems.

Done prompt injection / jailbreak / LLM application security research on an agentic or AI-powered product.

Previously shipped a coding agent, dev tool, or code-generation product end to end.

Relevant security certifications (OSCP, OSWE) or notable bug bounty / CTF history. Nice to have, not required for this role.

Enjoy building content and talking publicly about your work: blog posts, conference talks, or research writeups. We'd love for this role to help tell the story of how v0 approaches security, not just do the work quietly.