Ontrac is seeking a highly skilled and experienced Full-Stack AI Application Engineer to join a contractor program supporting a critical customer engagement. This role is ideal for a full-stack engineer who can own a feature end to end, from data model through user interface, and who has built and shipped applications on Google Cloud using Vertex AI and the Gemini models. The successful candidate should be equally comfortable writing Python services and React front ends, should be able to work from loosely defined requirements without heavy oversight, and will work closely with the delivery lead, the Program Manager, and customer stakeholders to ensure project success from initial definition through final delivery. ENGAGEMENT • Expected start date: 4 October 2026 • Location: United States only, fully remote REQUIRED CREDENTIALS • 8 or more years of professional software engineering experience • Demonstrated experience designing, building, and deploying applications on Google Cloud Platform • Google Cloud Professional certification, for example Professional Cloud Developer or Professional Machine Learning Engineer • A degree in Computer Science or a related field, or equivalent practical experience REQUIRED QUALIFICATIONS • Strong Python (3.11 and later), with production experience building REST APIs, ideally with FastAPI • Relational data modelling with SQLAlchemy and PostgreSQL • Hands-on experience with Vertex AI and the Gemini models through the google-genai SDK • Experience building agent and multi-agent workflows, ideally with Google's Agent Development Kit (ADK) • Front-end development with React 18 and TypeScript • Experience packaging and deploying containerized services to Cloud Run, and working with Cloud Storage • Comfortable writing and maintaining automated tests with pytest USEFUL QUALIFICATIONS • Retrieval and grounding with Vertex AI Search • Familiarity with the wider front-end toolchain: Vite, Tailwind, TanStack Query, and Zustand • End-to-end testing with Playwright • Local development with Docker Compose, and comfort with the gcloud CLI and pnpm • Prior delivery experience with a Google Cloud partner • Experience working directly with customer stakeholders in a consulting or delivery setting SCOPE AND DELIVERY EXPECTATIONS The following covers the scope of work we anticipate the contractor supporting throughout the project. This scope is in line with our expectations of the project but is subject to change. • Build and maintain the Python and FastAPI backend services, along with their PostgreSQL data models, that underpin the application • Implement agent and multi-agent workflows using Vertex AI, the Gemini models, and ADK, including retrieval and grounding through Vertex AI Search where the solution calls for it • Develop the React and TypeScript front end that surfaces these capabilities to end users • Package and deploy services to Cloud Run and manage application data and artifacts in Cloud Storage • Write and maintain automated tests, using pytest and Playwright, to keep delivery stable as the application grows • Take part in working sessions with the delivery team and customer stakeholders to refine requirements, resolve technical questions, and demonstrate progress • Produce the technical documentation needed to support handover at the close of the engagement