Senior Security Engineer, AI Model and Application

Company Overview ImmunityBio is a vertically integrated commercial stage biotechnology company developing next-generation therapies that bolster the natural immune system to defeat cancers and infectious diseases. The Company's range of immunotherapy and cell therapy platforms, alone and together, act to drive and sustain an immune response with the goal of creating durable and safe protection against disease. Designated an FDA Breakthrough Therapy, ANKTIVA is the first FDA-approved immunotherapy for non-muscle invasive bladder cancer CIS that activates NK cells, T cells, and memory T cells for a long-duration response. The Company is applying its science and platforms to treating cancers, including the development of potential cancer vaccines, as well as developing immunotherapies and cell therapies that we believe sharply reduce or eliminate the need for standard high-dose chemotherapy. These platforms and their associated product candidates are designed to be more effective, accessible, and easily administered than current standards of care in oncology and infectious diseases. Why ImmunityBio?* ImmunityBio is developing cutting-edge technology with the goal to transform the lives of patients with cancer and develop next-generation therapies and vaccines that complement, harness and amplify the immune system to defeat cancers and infectious diseases.* Opportunity to join a publicly traded biopharmaceutical company with headquarters in Southern California.* Work with a collaborative team with the ability to work across different areas of the company.* Ability to join a growing company with professional development opportunities. Position SummaryThe Senior Security Engineer AI Model and Application is a hands-on, systems-level role at the intersection of security engineering and artificial intelligence, involving close interaction with ML engineering, product, platform, and SOC/security operations teams. The Senior Security Engineer will serve as the subject matter expert (SME) in AI and LLM security across the organization, owning end-to-end security of AI systems - from data and training pipelines to inference endpoints and user-facing features. This role will support security leadership in driving threat modeling, adversarial testing, red teaming, and the implementation of secure-by-design AI features in alignment with applicable regulatory frameworks including NIST AI RMF, NIST CSF, and SOC 2 Type 2.Essential Functions * Design, implementation, and maintenance of security controls across the full AI/ML lifecycle, including training data validation, model registry policies, deployment guardrails, and production monitoring for anomalous model behavior. * Develop and maintain comprehensive threat models for AI/ML systems, covering prompt injection, data leakage, model evasion and extraction, data poisoning, and agent hijacking scenarios. * Lead red teaming and adversarial testing of LLMs and agentic workflows - including jailbreak attempts, prompt injection, output manipulation, and business logic abuse - and drive remediation with engineering teams. * Partner with ML engineers to embed security into model development pipelines, including secure training, evaluation, and deployment processes, as well as secure use of RAG architecture, tooling integrations, and multi-agent workflows. * Implement and define policies for safe prompt and response handling, including PII and sensitive content detection, output filtering, and usage logging to support investigations and compliance requirements. * Work with security engineering to integrate AI telemetry into SIEM, EDR, and SOC workflows; define and maintain runbooks for AI-related security incidents and forensic investigations. * Lead the creation, modification, and maintenance of AI security documentation, including threat model reports, security specification documents, SOPs, data flow diagrams, and network topology documentation. * Stay current