Principal Software Engineer (Dublin, Ireland) at Toast

This hybrid role is based in Dublin, Ireland (Full relocation provided). Toast creates technology to help restaurants and local businesses succeed in a digital world, helping business owners operate, increase sales, engage customers, and keep employees happy. Because our technology is purpose-built for restaurants, by restaurant people - and increasingly shaped by AI in both what we build and how we build - restaurants can trust that we'll deliver on their needs for today while investing in the experiences that will power their restaurant of the future. An AI pod is Toast's AI-native engineering team, a focused pod of specialists who tackle complex, high-impact problems across Toast's product and platform landscape using AI-first approaches. As a Principal Software Engineer, you'll work full-stack across ambitious, cross-cutting initiatives, bringing deep technical expertise and architectural judgment to some of the hardest problems at Toast. A day in the life (Responsibilities) • Lead full-stack design and delivery of AI-native solutions that address complex, cross-functional problems across Toast • Drive technical architecture for pod initiatives, from backend services and APIs to frontend and developer-facing interfaces • Build and integrate LLM-powered agents, tools, and workflows that bring AI capabilities directly into product and platform contexts • Set and uphold engineering standards within the pod: code quality, system design, testing, and operational practices • Mentor engineers through design reviews, code reviews, and pairing • Partner with stakeholders across Toast engineering to define problem scope, align on approach, and deliver outcomes • Serve as a technical voice in cross-team architecture discussions, connecting pod work to broader Toast engineering patterns What you'll need to thrive (Requirements) • 10+ years of experience designing and delivering scalable software systems, with a strong full-stack background spanning backend services and frontend or developer-facing interfaces • Demonstrated experience leading technical architecture for a platform, product, or engineering team • Experience building, deploying, or operating LLM-powered agents or AI platform infrastructure • Familiarity with AI coding assistants (e.g., Claude Code, Cursor, GitHub Copilot) and experience extending them through custom plugins, skills, or hooks • Experience with MCP (Model Context Protocol), tool use patterns, or similar agentic integration frameworks • Strong prompt engineering skills and intuition for how LLM behavior responds to context and instructions • Strong foundation in modern backend (Java, Kotlin, or similar) and frontend (TypeScript, React, or similar) technologies • A bias towards action and comfort operating in ambiguous, rapidly evolving problem spaces What will help you stand out • Familiarity with A2A (Agent-to-Agent) protocols and multi-agent orchestration patterns • Experience with machine learning concepts, model evaluation, or ML infrastructure • Experience building developer experience platforms or internal tooling • Familiarity with observability tooling for AI/LLM systems (e.g., Langfuse, DataDog) AI at Toast At Toast, one of our company values is that we're hungry to build and learn. We believe learning new AI tools empowers us to build for our customers faster, more independently, and with higher quality. We provide these tools across all disciplines, from Engineering and Product to Sales and Support, and are inspired by how our Toasters are already driving real value with them. The people who thrive here are those who embrace changes that let us build more for our customers; it’s a core part of our culture. Our Total Rewards Philosophy We strive to provide competitive compensation and benefits programs that help to attract, retain, and motivate the best and brightest people in our industry. Our total rewards package goes beyond great earnings potential and provides the means to a healthy lifestyle with the flexibility to meet Toasters’ changing needs. Learn more about our benefits at [Upgrade to PRO to see link] #LI-Hybrid #BI-Hybrid How Toast Uses AI in its Hiring Process Throughout the hiring process, our goal is to get to know you. We use AI tools to support our recruiters and interviewers with tasks like note-taking, summarization, and documentation of interviews to ensure they can be fully focused on your conversation. All hiring decisions are made by people. To learn more: [Upgrade to PRO to see link] Diversity, Equity, and Inclusion is Baked into our Recipe for Success At Toast, our employees are our secret ingredient—when they thrive, we thrive. The restaurant industry is one of the most diverse, and we embrace that diversity with authenticity, inclusivity, respect, and humility. By embedding these principles into our culture and design, we create equitable opportunities for all and raise the bar in delivering exceptional experiences. We Thrive Together We embrace a hybrid work model that fosters in-person collaboration while valuing individual needs. Our goal is to build a strong culture of connection as we work together to empower the restaurant community. To learn more about how we work globally and regionally, check out: [Upgrade to PRO to see link] Apply today! Toast is committed to creating an accessible and inclusive hiring process. As part of this commitment, we strive to provide reasonable accommodations for persons with disabilities to enable them to access the hiring process. If you need an accommodation to access the job application or interview process, please contact [Upgrade to PRO to see contact]. ------ For roles in the United States, it is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.