Partner 34, Lead, Security Engineering

a16z•San Francisco, CA

13h•Hybrid

About The Position

Founded in Silicon Valley in 2009 by Marc Andreessen and Ben Horowitz, Andreessen Horowitz (aka a16z) is a venture capital firm that backs bold entrepreneurs building the future through technology. We are stage agnostic. We invest in seed to venture to growth-stage technology companies, across AI, bio + healthcare, consumer, crypto, enterprise, fintech, games, and companies building toward American dynamism. a16z has $100B+ under management across multiple funds. We’ve established a team that is defined by respect for the entrepreneur and the company-building process; we know what it’s like to be in the founder’s shoes. We’ve invested in companies like Anduril, Airbnb, Coinbase, Cursor, Databricks, Deel, Figma, GitHub, Roblox, SpaceX, and Stripe. Our team is at the forefront of new technology, helping founders and their companies impact and change the world. The Role We're hiring a Security Engineering Lead to build and shape a16z's security engineering team. This is a hands-on role - you'll spend a real portion of your time in AI security conversations, code reviews, architecture conversations, and the harder build decisions. You'll own application security, enterprise security and cloud security across the firm, and you'll partner closely with our internal engineering organization (ASG) on the security of everything they ship, including the AI tooling that's increasingly central to how the firm runs. You'll report to the Head of Cybersecurity and work day to day with the SecOps Lead, ASG, a16z’s CTO and IT to make security show up as a partner, not a gate. Venture capital firms face targeted, sophisticated threats — capital call wire fraud, social engineering, vishing, and threat actors who specifically pursue firms in this space. Your work protects the firm, our LPs, and our portfolio companies.

Requirements

7+ years of security engineering experience or equivalent demonstrated impact, with depth in both AppSec and CloudSec
Track record of leading cross-functional projects and managing senior stakeholders
Experience leading or significantly contributing to small teams (3 to 5 people). Formal management experience preferred but not required
Comfortable running code reviews, threat models, and architecture discussions yourself
Strong working knowledge of modern cloud and SDLC tooling (Terraform, Kubernetes, GitHub Actions, SAST, SCA, secrets scanning)
Experience operating in environments where security needs to enable the business rather than gate it
AI security knowledge, including model risk, prompt injection, and agent governance. This is a growing area for us
Experience translating technical security concepts, decisions, and trade-offs into terms non-technical audiences across the firm can act on
Low ego, high empathy, and the capacity to collaborate effectively with diverse teams

Responsibilities

Own AppSec and CloudSec across AWS and GCP, including the roadmap, the tooling stack, and the engineering partnership
Help secure a16z's AI work, including internal AI tooling, agent governance, model risk, and prompt injection defense
Build a partnership with engineering where security shows up early, not after the fact
Stay technical day to day - code reviews, architecture conversations, threat models, and the harder build calls
Run and support cross-functional initiatives that span technical and non-technical teams across the firm, and own the relationships behind them