Sr. Staff AI Security Engineer

Innovate with purpose

At BILL we believe in empowering the businesses that drive our economy. By replacing outdated financial processes with innovative tools we help businessesfrom startups to established brandsmake smarter decisions and gain control of their operations. And we dont stop there: were creating the future of financial automation so businesses can spend more time on what matters.

Working here means you become part of a vision-driven team thats ready to tackle challenges and build cutting-edge solutions. We value purpose drive and curiosityand we thrive in a fast-paced ever-changing environment. Were remote-first with office spaces in San Jose CA and Draper UT and opportunities to connect in person when it counts. BILLders collaborate to deliver real impact for businesses that need more time in their busy weeks.

BILL builds high performing teams and we seek to hire the best talent for every role. Were committed to building a workplace that fosters inclusion and diverse perspectives valuing each persons unique skills and experiences. Wed love to hear from youyou might be just what were looking for whether in this role or another.

Lets give businesses more time for what matters.

Make your impact within a rapidly growing Fintech Company

We are looking to hire a Sr. Staff AI Security Engineer to lead the secure deployment and operation of AI and ML systems across the company. This role moves beyond traditional perimeter security to address the unique vulnerabilities of Large Language Models (LLMs) and automated orchestration layers. Your mission: provide a secure foundationgateways orchestration layers and tool ecosystemsthat enables developers to innovate at pace while maintaining a robust security posture.

Youll partner with platform engineering and IT teams as a builder and enabler rather than a gatekeeper embedding security into the AI development lifecycle by default and shaping how BILL navigates the AI threat landscape.

Secure AI Architecture & Infrastructure: Design and implement secure gateways that act as controlled entry points for AI requests ensuring all interactions are authenticated and logged. Build orchestration layers that enforce security policies (rate limiting content filtering) across multiple AI models and providers. Integrate security controls into developer tool ecosystems so security is baked in by defaulthighly available scalable via infrastructure as code and never a performance bottleneck for production AI applications.

Adversarial Research & Red-Teaming: Own and stand up a formal AI red-teaming practice to identify vulnerabilities before they reach production. Research and simulate advanced attack vectors including prompt injection jailbreaking adversarial suffixes model extraction model poisoning training data leakage and AI supply chain compromise. Systematically document findings and deliver clear remediation paths to engineering teams.

Strategic Leadership: Own the long-term AI security roadmap aligning technical goals with BILLs business mission. Act as the primary subject matter expert advising senior leadership on AI risk. Mentor engineers across the organization to raise BILLs collective security IQ.

Responsibilities

• Design build and operate secure AI gateways and policy orchestration layers spanning multiple AI models and service providers
• Configure end point settings for AI tools in collaboration with IT end point management solutions.
• Stand up and lead a formal AI red-teaming practice covering prompt injection jailbreaking model extraction and emerging attack vectors
• Identify and mitigate AI-specific threats across input manipulation supply chain (model weights datasets third-party AI libraries) data privacy (training data leakage PII disclosure) and model integrity (poisoning unauthorized fine-tuning)
• Automate security checks and guardrails to enable rapid development cycles without sacrificing security posture
• Apply and operationalize the OWASP LLM Top 10 framework to categorize and mitigate risk
• Own the AI security roadmap and advise senior leadership on AI risks and safe adoption
• Embed with platform teams as a partner fostering a collaborative security culture
• Mentor fellow engineers on AI security best practices
• Document and report vulnerabilities with clear remediation guidance and technical direction

Wed love to chat if you have:

• A proven track record of building and scaling security systems in high-growth environments
• High proficiency in Python or Go to build automate and scale security tooling
• Deep understanding of LLM-specific attack vectors: prompt injection and jailbreaking
• Deep understanding and applied experience with the OWASP LLM Top 10 framework
• Experience designing secure API gateways orchestration layers and scalable security infrastructure using infrastructure as code
• Experience standing up red-teaming or adversarial testing programs
• A strong grasp of AI/ML fundamentals including model supply chain and data privacy risks
• A builder mentality and passion for the AI spaceyou enable development through secure architecture rather than blocking it
• The ability to influence senior leadership and mentor engineers across the organization
• A background in Computer Science Cybersecurity or a related technical field

Visa Sponsorship: Please note that this position is not eligible for visa sponsorship. Applicants must have authorization to work in the United States without requiring visa sponsorship now or in the future.

#LI

Whats in it for you

Redefining how businesses automate their work is a fast-paced exciting and fun environment. But we also have benefits and perks to ensure the magic isnt only experienced by our customers but by our employees as well.

Here is a preview of some of the amazing benefits here at BILL:

• 100% paid employee health dental and vision plans (choose HMO PPO or HDHP)
• HSA & FSA accounts
• Life Insurance Long & Short-term disability coverage
• Employee Assistance Program (EAP)
• 11 Observed holidays and wellness days and flexible time off
• Employee Stock Purchase Program with employee discounts
• Wellness & Fitness initiatives
• Employee recognition and referral programs
• And much more

Dont believe us Check out our culture benefits and teams on our career site LinkedIn Life or YouTube pages.

BILL is an Equal Opportunity Employer. We believe our best ideas come from the unique stories perspectives and experiences of our team members. We welcome people of all backgrounds abilities and identities to bring their authentic selves and contribute to our culture.

We are committed to a transparent inclusive hiring process that reflects our values. If you need accommodations at any stage please contact . To ensure a fair evaluation our Candidate Integrity Policy prohibits the use of unapproved external assistance including generative AI during live interviews or assessments. Doing so will result in a review and potential disqualification.

Our Applicant Privacy Notice describes how BILL treats the personal information it receives from applicants.