Principal API Architect, Product Engineering – Agent‑Ready APIs & Data

Workday•Pleasanton, CA

18h•Hybrid

About The Position

Product Engineering builds the end-to-end product experiences that Workday customers use. Many of these experiences are now powered by agents and AI, which depend on a strong API foundation. This role sits in Product Engineering but operates across product pillars. You will work closely with Product Engineering teams as well as partner organizations. You will shape the API foundation, architecture and operating model that makes it easy for Product Engineering to build agent ready, high quality APIs.

Requirements

12+ years of experience building large‑scale, mission‑critical backend systems and APIs.
5+ years in a senior architecture or staff‑plus role with responsibility for cross‑team or organization‑wide API/platform architecture.
Deep hands‑on experience using TypeScript or Python to build web services and APIs (REST, SOAP, GraphQL, JSON, XML, WSDL, Swagger/OpenAPI)
Understanding of the MCP protocol specification and architecture
Proven track record of setting and driving technical standards that scale across multiple teams.
Able to prototype reference implementations and dive into code reviews when needed

Nice To Haves

Experience leveraging AI‑assisted code generation and review tools (e.g., Cursor, Claude Code, GitHub Copilot) to improve development speed and quality.
Strong expertise in distributed systems and cloud architectures, including high‑throughput, low‑latency services, horizontal scaling, and fault‑tolerant design.
Extensive experience with edge and gateway patterns (routing, auth, throttling, rate limiting, transformation, multi‑tenant concerns).
Demonstrated leadership in API governance: standards definition, contract review, documentation, and lifecycle management.
Experience designing or evolving observability for APIs (metrics, tracing, logging) and using that data to define and monitor SLOs.
Familiarity with agentic AI use cases and patterns for integrating LLMs/agents with enterprise APIs
Experience with data platforms and analytical stores (such as Data Cloud or equivalent) and designing APIs that expose data safely and efficiently.
Ability to collaborate and influence across Product Engineering, platform teams, and business stakeholders.
Excellent written and verbal communication skills; able to articulate complex technical topics in simple, compelling terms.
Passion for growing others: mentoring staff‑level engineers, supporting managers, and building a strong API culture within Product Engineering.
Growth mindset and comfort working in evolving spaces where the operating model is still being defined.

Responsibilities

Act as the “Chief API Architect” for Product Engineering.
Define and evolve the API architecture, standards, and review processes that guide how Product Engineering teams design and deliver APIs.
Partner with product and platform leaders to shape the operating model, including API champions across product pillars and a clear intake/prioritization path for API needs.
Define the API architecture and governance model for Product Engineering, spanning REST, GraphQL, SOAP, and emerging integration models used by Workday agents and products.
Establish and maintain API standards: OpenAPI contract guidelines, review and approval process. Resource modeling, naming and pagination conventions. Authentication/authorization and multi‑tenant patterns. Error handling, retry semantics, and idempotency guidelines. Versioning and deprecation policies.
Partner with Product Engineering leaders and “API champions” in each product area to shape their API roadmaps, identify gaps or duplication, and drive convergence on shared patterns and building blocks.
Define reference architectures and patterns for agent-ready APIs and orchestration patterns used by the Agent Factory, and data-centric APIs, including how Product Engineering safely exposes data via Data Cloud / SQL projections.
Define latency and observability standards across the end‑to‑end request path.
Lead critical cross‑team API design reviews and act as the tie‑breaker on contentious or high‑impact design decisions.
Work closely with platform partners (Gateways, Trident, Web Service Frameworks, Core Services, Data Cloud, AI/Agent Factory) to ensure Product Engineering’s needs are represented and that platform capabilities are consistently applied.
Shape and help run a single, transparent intake and prioritization process for key Product Engineering API investments.
Evaluate build/borrow/buy options for tools that help Product Engineering design, test, and operate APIs (including contract testing, catalogs, MCP/Data Cloud connectors, and developer tooling).
Mentor senior engineers and managers on API architecture, distributed systems, and integration best practices; build communities of practice across Product Engineering.
Communicate the API vision and status to senior stakeholders and help influence product and resourcing decisions.