Senior Security Software Engineer, v0 in London

About Vercel: Vercel is the agentic infrastructure company. We free people and agents to ship what’s next. For more than a decade, Vercel has shaped how the web is built. As the team behind Next.js, v0, and AI SDK, we create products that help builders move from idea to production with speed, security, and exceptional developer experience. Now, software is entering a new era, and the next generation of products will not just be used by people. They will be built, extended, and operated by agents. We are building the platform for that future, trusted by companies like OpenAI, PayPal, Ramp, Supreme, and millions of developers worldwide.

About the role: 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.

What you will do:

• Find and fix issues yourself: Proactively hunt for vulnerabilities across v0, from code you're reviewing to systems you're actively poking at, and ship the fix, not just the finding.
• Build security features directly into the product: Design and implement the security-facing functionality itself (sandboxing/isolation controls, permission boundaries, abuse detection, safe defaults for generated apps) as a normal part of the v0 roadmap, not a side project.
• Review all new v0 features and launches: Be the security reviewer of record for everything the team ships (new capabilities, generated-app patterns, integrations) before it goes out the door.
• Own the HackerOne relationship for v0: Triage, validate, and drive fixes for reports from Vercel's HackerOne researcher community that touch v0, and work directly with researchers on reproduction and remediation.
• Own the v0 threat model: Understand and continuously refine how v0 generates, executes, and deploys code, including sandbox/runtime isolation, permission boundaries between agent actions and user intent, and defenses against prompt injection and tool-use abuse.
• Harden code execution boundaries: Work directly on how agent-generated code is scoped, sandboxed, and constrained before it touches real infrastructure, including Vercel's own sandbox and serverless runtimes.
• Build guardrails that don't slow the team down: Create patterns, libraries, and checks that let v0 engineers ship new generated-app capabilities quickly without reintroducing known bug classes (auth, SSRF, injection) each time.
• Partner with central Product Security: Share threat models, incident learnings, and SDLC tooling with the broader security team, while making the final call on v0-specific tradeoffs since you have the deepest context on the product.
• Respond to v0-specific security reports and incidents: Be the first responder and technical owner when a security issue is reported against v0 specifically.
• Think like an attacker, and like an agent: Reason about how a user, or an agent acting on that user's behalf, could misuse v0 to attack itself, other tenants, or the platform underneath it.

About you:

• You're a software engineer first: 5+ years building and shipping production web applications, at a level where you operate independently (IC4/Senior).
• 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.
• 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.

Bonus if you have:

• 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.
• Enjoy building content and talking publicly about your work: blog posts, conference talks, or research writeups.

Benefits:

• Competitive compensation package, including equity.
• Inclusive Healthcare Package.
• Learn and Grow - we provide mentorship and send you to events that help you build your network and skills.
• Flexible Time Off.
• We will provide you the gear you need to do your role, and a WFH budget for you to outfit your space as needed.

Vercel is committed to fostering and empowering an inclusive community within our organization. We do not discriminate on the basis of race, religion, color, gender expression or identity, sexual orientation, national origin, citizenship, age, marital status, veteran status, disability status, or any other characteristic protected by law. Vercel encourages everyone to apply for our available positions, even if they don't necessarily check every box on the job description.