Senior AI Engineer - Model Selection and Orchestration

• Senior AI Engineer with experience building production AI systems, model orchestration, tool calling, retrieval, and modern software engineering practices to build reliable AI capabilities across customer-facing and internal experiences.
• Hands-on engineer who owns components of the decision and orchestration layer that determines when agents should use a model, tool, retrieval system, or deterministic workflow, balancing quality, safety, latency, reliability, and cost.
• Remote-first opportunity for US-based employees with the option to work in-person out of our Manhattan office.

Become a part of Zip's Engineering team and take on exciting challenges at the intersection of AI, software engineering, and financial technology. At Zip, our engineers build systems that move real money and serve millions of customers, making reliability, security, and sound engineering judgment fundamental to how we build.

We are seeking a Senior AI Engineer to help turn rapidly evolving AI capabilities into dependable customer experiences and useful tools for our teams. You’ll work within our AI Platforms team, building shared capabilities that support Zia, our customer-facing AI experience, as well as internal agents and AI-powered workflows across Zip.

You’ll play a hands-on role in designing and building the decision and orchestration layer that helps agents interpret requests and determine the right execution approach. Depending on the task, that could mean deterministic logic, retrieval, a lightweight classifier, an AI model, a tool call, or a more complex reasoning workflow. You’ll use evidence about task quality, safety, latency, reliability, and cost to recommend and implement those decisions.

This is a builder’s role where you’ll write production code, evaluate AI system behavior, integrate models and tools, contribute to technical decisions, and work closely with Principal and Staff Engineers, Product, domain engineering, Security, and Risk. You’ll use managed capabilities within the Gemini Enterprise Agentic Platform (GEAP) and approved cloud tooling, while building Zip-specific orchestration, decision logic, and integrations where needed.

• Build Intelligent Decision and Routing Systems: Design and implement the decision layer that determines how an agent should respond to a task, including when to use deterministic logic, retrieval, smaller models, reasoning models, tools, or human escalation.
• Build Intent and Clarification Flows: Develop intent classification and clarification capabilities that distinguish information requests from actions, identify ambiguous requests, evaluate confidence, and determine when additional information or escalation is required.
• Evaluate and Select Models: Benchmark rules, retrieval approaches, classifiers, smaller models, and reasoning models against representative tasks. Use measurable outcomes such as task success, quality, latency, safety, and total inference cost to recommend model-selection decisions.
• Build Reliable Model Orchestration: Implement and improve model adapters, routing logic, structured outputs, timeouts, retry strategies, fallback behavior, and observable failure handling. Build orchestration that is testable and avoids unnecessary dependency on any single model provider.
• Integrate Models, APIs, and Tools Safely: Connect agents to approved APIs and tools with appropriate authentication, authorization, policy checks, and customer confirmation. Design for duplicate requests, idempotency, recovery, and other failure scenarios when agents perform state-changing actions.
• Build Secure AI Systems: Partner with Security and Risk to implement approved input and output protections, sensitive-data…