Software Development Engineer III / Sr. Software Development Engineer - AI Platform

Workday•Boulder, CO

8d•$148,200 - $264,000•Hybrid

About The Position

Workday is a Fortune 500 company and a leading AI platform for managing people, money, and agents. The Agent Runtime team builds Workday’s secure execution platform for enterprise AI agents, creating the runtime substrate that enforces policy by architecture, not by prompt, with deterministic controls for data access, tool use, model routing, and auditability. The charter spans runtime isolation, policy enforcement boundaries, model mediation, and observability at scale. The team partners closely with other engineering and platform teams at Workday to deliver a multi-language, enterprise-grade agent runtime. As a Senior Software Development Engineer, you will design and build core runtime capabilities for policy-governed agent execution. You will own high-impact technical areas across sandbox execution, sidecar interfaces, enforcement flows, and production reliability. This includes designing and implementing core runtime services for secure, isolated agent execution, building deterministic enforcement pathways for data, context, tool, and model boundaries, defining and evolving service interfaces and contracts across maincar and sidecar components, improving performance, scalability, and resilience for high-concurrency workloads, building deep observability into runtime behavior, policy decisions, and audit traces, partnering with cross-functional teams to integrate data prep, context assembly, tool gating, and model mediation, participating in architecture reviews, incident response, and operational hardening, and mentoring engineers and helping raise engineering quality across the team. As a Software Development Engineer III on the Agent Runtime team, you will implement key runtime components and services that power secure agent execution. You will contribute to design, coding, testing, and operations for systems that enforce policy and reliability guarantees in production. This includes building backend services and runtime components for cell lifecycle and execution control, implementing policy-aware data, context, tool, and model access pathways, contributing to interface development between runtime components and partner systems, writing high-quality, testable code and participating in code and design reviews, developing telemetry and logging capabilities for traceability and operational insight, supporting production operations, performance tuning, and incident follow-through, and collaborating closely with senior engineers and partner teams on roadmap delivery.

Requirements

8+ years experience in software development engineering, architecting, building, and scaling robust and efficient software systems (Sr. SWE)
6+ years of software engineering experience building backend or platform systems (Sr. SWE)
5+ years experience in software development engineering including designing, developing, and deploying software solutions (SWE III)
3+ years of software engineering experience in backend or platform development (SWE III)
Strong experience with distributed systems, APIs, and service-oriented architecture.
Experience building secure systems with least-privilege patterns and policy controls.
Proficiency in at least one systems or backend language (for example, Java, Go, Rust, or Python).
Experience operating production services with strong reliability and observability practices.
Demonstrated ownership of complex technical projects from design through production.
Strong collaboration and communication skills in cross-functional environments.
Solid foundation in distributed systems fundamentals, APIs, and data modeling.
Proficiency in one or more programming languages used for backend systems.
Experience building and shipping production services with testing and monitoring.
Working knowledge of security fundamentals, including authentication, authorization, and least-privilege concepts.
Ability to debug complex issues and deliver reliable fixes in production environments.
Strong written and verbal communication skills and effective team collaboration.

Responsibilities

Design and implement core runtime services for secure, isolated agent execution.
Build deterministic enforcement pathways for data, context, tool, and model boundaries.
Define and evolve service interfaces and contracts across maincar and sidecar components.
Improve performance, scalability, and resilience for high-concurrency workloads.
Build deep observability into runtime behavior, policy decisions, and audit traces.
Partner with cross-functional teams to integrate data prep, context assembly, tool gating, and model mediation.
Participate in architecture reviews, incident response, and operational hardening.
Mentor engineers and help raise engineering quality across the team.
Build backend services and runtime components for cell lifecycle and execution control.
Implement policy-aware data, context, tool, and model access pathways.
Contribute to interface development between runtime components and partner systems.
Write high-quality, testable code and participate in code and design reviews.
Develop telemetry and logging capabilities for traceability and operational insight.
Support production operations, performance tuning, and incident follow-through.
Collaborate closely with senior engineers and partner teams on roadmap delivery.