Exa is an applied AI lab building a search engine unlike the world has ever seen. We build massive-scale infra to crawl the entire web, train state-of-the-art embedding models to process it, and design super high performant vector databases to retrieve over it. We now power search for Cursor, Cognition, HubSpot, and over 400,000 developers and have raised $350m from Lightspeed, Benchmark, and a16z. Our ultimate goal is to build perfect search over all the world's information, far beyond Google. If you want to build massive-scale ML systems that will define the way the new AI world consumes information, this is the place for you. We are hiring a Security Engineer to build the protective shield for all of Exa’s systems. These systems include: processing web scale data, indexing hundreds of billions of pages, training foundational models on TBs of data, serving thousands of enterprise customers from our endpoints. You will be critical in making Exa run securely while ensuring our shipping velocity. Desired Experience - You have hands-on experience in building and maintaining secure infrastructure - You know your way around cloud security fundamentals, including multi-account AWS permissions and architectures, IAM design, secure CI/CD pipelines - You are fluent in secrets management, key management, and certificate lifecycles (rotation, revocation, automation) - You have owned compliance efforts such as HIPPA, SOC2, etc. - You are comfortable with security hardening and any other details needed to make engineering systems run smoothly (VPN, development servers, etc.) - You are super vigilant about vulnerabilities, potential attacks, and abuse, and constantly think about how to operate securely with the introduction of new technologies (OS-level, AI coding agents, etc.) Example Projects - Build a secrets management and rotation system used across distributed services, training jobs, and GPU clusters without impacting developer velocity - Build monitoring and alerting for anomalous behavior across APIs, internal services, and customer usage - Create security incident response playbooks and lead incident handling, from detection to post-mortem This is an in-person opportunity in San Francisco. We're happy to sponsor international candidates (e.g., STEM OPT, OPT, H1B, O1, E3). In addition to premium healthcare benefits (medical, dental, vision), we also offer fertility benefits and a monthly wellness stipend to all of our employees. Exa is an equal opportunity employer. All qualified applicants will receive consideration for employment without regard to race, creed, color, religion, sex, sexual orientation, gender identity or expression, national origin, disability, age, veteran status, marital status, pregnancy or related conditions, criminal histories consistent with applicable law, or any other basis protected by applicable law.