Senior Software Engineer - API Platform (Python/Typescript)
About the Role
As a Senior Software Development Engineer in Product Engineering, you will be a technical leader in designing and delivering high‑throughput, low‑latency APIs and frameworks that support Workday's next generation of products and agents. You will shape API design, drive performance and observability improvements, and coach and grow future senior engineers across the team.
You will:
Lead design and implementation of APIs and platform features used by Product Engineering teams.
Champion consistent API standards, patterns, and tooling that align with cross‑org guidance while solving concrete product needs.
Help Product Engineering teams expose capabilities via REST, GraphQL, and emerging integration patterns in a way that is friendly to agents and external consumers.
What you’ll do
Lead end‑to‑end design and development of complex backend services and APIs.
Drive consensus with product managers, architects, and partner teams to define clear, evolvable API contracts and data models, using OpenAPI and internal standards.
Drive performance and scalability improvements, including latency optimization, capacity planning, and resiliency strategies for mission‑critical product flows.
Design and implement observability for product APIs (metrics, tracing, structured logging), and use data to drive technical decisions and SLOs.
Collaborate on frameworks, tools, and patterns that make it simpler for other Product Engineering teams to define, publish, and maintain APIs.
Work with data platform teams to define patterns for exposing data safely and efficiently to API and agent workflows.
Provide technical leadership through design reviews, RFCs, spike investigations, and coaching junior engineers.
Participate in and improve on‑call and incident response processes; own root cause analysis and long‑term remediation for significant issues.
Act as a trusted technical partner to teams across Product Engineering, helping them make API and integration decisions.
About You
Basic Qualifications
8+ years of experience designing and building large‑scale, mission‑critical backend systems.
5+ years of hands‑on experience with TypeScript or Python and strong OO/functional design skills.
4+ years of experience building and operating web service APIs (REST/SOAP/GraphQL) at scale.
Demonstrated experience owning complex features or systems from design through production.
Other Qualifications
Comfort using AI‑assisted code generation tools (such as Cursor, Claude Code, GitHub Copilot) as part of the day‑to‑day development workflow.
Deep understanding of distributed systems: concurrency, multithreading, consistency, fault tolerance, and performance tuning.
Strong experience with API design and lifecycle: OpenAPI/Swagger, versioning strategies, backward compatibility, contract testing, and documentation.
Experience with API gateway or edge patterns (routing, authentication/authorization, throttling, rate limiting, transformation, multi‑tenant concerns).
Hands‑on experience with observability stacks (metrics, tracing, logging) and using them to improve latency and reliability.
Familiarity with GraphQL and data‑oriented APIs; exposure to Data Cloud / analytical stores or MCP‑style agent integration patterns is a plus.
Strong testing discipline (unit, integration, contract, performance) and experience with modern testing and observability stacks such as JUnit, ScalaTest, Postman, Mockito, Jacoco/Scoverage.
Experience with cloud and containerized environments (e.g., AWS, Kubernetes) and CI/CD pipelines.
Proven track record of mentoring engineers, leading technical discussions, and driving cross‑team initiatives.
Ability to translate product and AI/agent requirements into robust API and backend designs.
Comfort working in ambiguous problem spaces with a bias for pragmatic, iterative delivery.
Workday Pay Transparency Statement (For EU Locations Only)
Listed below is the base salary range applicable to this position. Workday pay ranges (and the precise pay offered to the successful candidate) are based on a number of objective criteria such as relevant experience and skills, and educational qualifications, level of responsibility, demands of the role, work location and business need. As a part of the total compensation package, this role may be eligible for the Workday Bonus Plan or a role-specific commission/bonus, as well as annual refresh stock grants awarded by Workday Inc. For more information regarding Workday’s comprehensive benefits, please .
Primary Location Base Pay Range: €86,400 EUR - €129,600 EUR Ireland