Senior Software Engineer (Agentic AI & API Platform)

Workday; Ireland; On-site; EUR 70,000 - 90,000; Full time

Job summary

Workday is looking for a Senior Software Development Engineer in Ireland. This role involves designing and delivering high-throughput APIs, leading development, and fostering collaboration across teams. You will enhance API resilience and performance, while mentoring junior engineers and driving alignment on design standards.

The ideal candidate will have extensive experience with TypeScript or Python, a solid background in distributed systems, and a passion for technical leadership.

Qualifications

• Experience managing production observability for critical services.
• Hands-on experience with TypeScript or Python in production.
• Years of experience designing and maintaining scalable web APIs.

Responsibilities

• Lead the design and development of high-throughput APIs.
• Drive improvements in API performance and resilience.
• Provide technical leadership and mentoring to junior engineers.

Skills

Python

TypeScript

API design

Distributed systems

Observability

Algorithms

Technical writing

DevOps practices

Tools

JUnit

Git

Postman

Job description

Responsibilities

• 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 power Workday’s next generation of products and agents.
• You will shape API design, drive performance and observability improvements, and help grow future senior engineers across the team.
• This role is crucial because agentic AI changes how APIs must be built. For an AI agent to successfully process an invoice, update an employee record, or orchestrate a complex workflow within Workday, the underlying APIs must be highly deterministic, self-describing, and resilient. You will be at the center of making that possible.
• Lead end-to-end design and development of complex backend services and APIs used by Product Engineering teams.
• Drive consensus with product managers, architects, and partner teams to define clear, evolvable API contracts and data models using OpenAPI and internal standards.
• Champion consistent API standards, patterns, and tooling that align with cross-organization 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.
• 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 inform 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 sound API and integration decisions.

Qualifications

• 2+ years of experience implementing and managing production observability (e.g., structured logging, distributed tracing, metrics) and owning on-call/incident remediation for critical services.
• 3+ years of experience working with distributed systems architecture, handling high-throughput workloads, concurrency management, or advanced caching strategies.
• 5+ years of hands‑on experience with TypeScript or Python in production environments.
• 4+ years of dedicated experience designing, building, and maintaining scalable web APIs (REST and/or GraphQL) with a strong emphasis on contract-first design (e.g., OpenAPI/Swagger).
• 8+ years of experience in software development engineering, architecting, building, and scaling robust and efficient backend software systems.
• Strong ability in algorithmic thinking, including advanced data structures and algorithms such as graphs, concurrent data structures, and caching/eviction strategies, to design and optimize solutions for complex API orchestration, request routing, and high-throughput workloads.
• Proven ability to lead team collaboration within a software development team and mentor junior and mid‑level engineers through design reviews, technical guidance, and knowledge sharing.
• Strong understanding of object-oriented design (OOD) principles like SOLID, domain-driven design concepts, and common architectural patterns (e.g., layered architecture, hexagonal architecture) and their application in designing scalable software architectures.
• Strong skills in creating technical writing documentation for comprehensive technical specifications, design documents, RFCs, and API and integration best‑practice guides.
• Strong understanding of code testing methodologies, such as contract testing, performance testing, and system/integration testing, and experience with advanced testing tools or frameworks (e.g., JUnit, ScalaTest, Postman, Mockito, and coverage tools such as Jacoco or Scoverage).
• Exposure to MCP or similar models is a strong plus.
• Experience leveraging AI‑assisted code generation and review tools (e.g., Cursor, Claude Code, GitHub Copilot) to improve development speed and quality.
• Solid understanding of software development principles and advanced development methodologies such as continuous delivery, trunk-based development, and test-driven or behavior-driven development.
• Solid experience with source control management (SCM) tools such as Git and advanced branching and merging strategies across multiple teams or services.