Senior Software Engineer - AI Foundations at Toast

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. AI Foundations is Toast's internal platform team for AI. We build the infrastructure, governance, and developer tooling that makes AI a reliable, scalable force multiplier across the entire product development lifecycle. Our products include the LLM Proxy, AI Key Management, Observability pipelines, the Claude Plugin Marketplace, and autonomous agents that participate directly in the software development lifecycle. As a Senior Software Engineer on this team, you'll be hands-on building full-stack across the systems other Toast engineers depend on every day: the LLM proxy, agentic workflows, and the plugin marketplace that brings AI-native development practices to teams across the company. A day in the life (Responsibilities) • Design, build, and ship features across AI platform infrastructure, including the LLM proxy, AI key management, and observability pipelines • Develop and extend autonomous agents that participate in the SDLC, such as the AI Review GitHub App and Developer Platform MCP integrations • Build on and contribute to the internal plugin marketplace, developing plugins that encode Toast's architectural standards and quality practices into AI assistant behavior • Implement MCP (Model Context Protocol) services and service templates that make it faster and easier for teams across Toast to build AI-powered workflows • Contribute full-stack across backend services and frontend or developer-facing interfaces as needed • Write high-quality, well-tested code and participate in design and code reviews • Partner closely with product management to shape feature requirements, contribute to roadmap discussions, and translate product vision into reliable technical solutions What you'll need to thrive (Requirements) • 5+ years of experience designing and implementing scalable software systems, with a full-stack background spanning backend services and frontend or developer-facing interfaces • Demonstrated experience building, deploying, or operating LLM-powered agents or AI-assisted developer tooling • Familiarity with AI coding assistants (e.g., Claude Code, Cursor, GitHub Copilot) and an interest in extending them through custom plugins, skills, or hooks • Experience with MCP (Model Context Protocol), tool use patterns, or agentic frameworks • Working knowledge of prompt engineering and how LLM behavior responds to context and instructions • Strong foundation in modern backend (Java, Kotlin, or similar) and frontend (TypeScript, React, or similar) technologies • Experience with distributed systems, REST APIs, and cloud-native infrastructure • Strong customer empathy and a drive to make developers' lives better through reliable, well-designed platform solutions What will make 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, internal tooling, or API gateways • 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] 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.