Principal Software Engineer (AI Foundations)

• 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 Principal Software Engineer, you’ll set the technical direction for how we design, build, and evolve these systems, working full-stack across the agentic workflows that employees across Toast depend on every day. This role is for someone who can drive architecture, raise the engineering bar across the team, and stay hands-on building
• Define and drive the technical architecture for AI Foundations platform, spanning backend services, frontend tooling, and third party integrations
• Lead full-stack design and delivery across the LLM proxy, AI key management, observability pipelines, and internal plugin marketplace
• Architect and deliver autonomous agents and MCP services that participate in the software development lifecycle
• Set and uphold engineering standards across the team: code quality, system design, testing, and operational practices
• Mentor and technically lead engineers across all levels through design reviews, code reviews, and pairing
• Partner with product and platform leadership to shape the AI Foundations roadmap and translate strategy into executable technical plans
• Collaborate closely with designers and product teams to translate UX concepts into polished, production-ready frontend experiences
• Serve as a key technical voice in cross-team discussions, representing AI Foundations in architecture decisions across Toast engineering

Benefits

• Peer and company recognition programs
• Unlimited Vacation
• Sabbatical opportunity after five years
• Professional Development Reimbursement Program
• Commitment to Employee Wellness through resources such as a quarterly Wellness Stipend
• Various peer and company recognition programs
• 401(k) and matching
• Medical, Dental, & Vision Coverage
• Mental Health Benefits
• Subsidized backup childcare

• Demonstrated experience leading technical architecture for a platform, product, or engineering team
• Comfort with a rapidly changing technical landscape and a bias towards action over analysis paralysis
• Familiarity with AI coding assistants (e.g., Claude Code, Cursor, GitHub Copilot) and experience extending them through custom plugins, skills, or hooks
• 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
• Experience building, deploying, or operating LLM-powered agents or AI platform infrastructure
• Experience with MCP, tool use patterns, or agentic frameworks
• Strong foundation in modern backend (Java, Kotlin, or similar) and frontend (TypeScript, React, or similar) technologies, with demonstrated experience building user-facing product interfaces
• Proven ability to mentor engineers and raise the technical bar of a team through standards, reviews, and hands-on guidance
• Familiarity with A2A (Agent-to-Agent) protocols and multi-agent orchestration patterns
• Experience with machine learning concepts, model evaluation, or ML infrastructure
• Familiarity with observability tooling for AI/LLM systems (e.g., Langfuse, DataDog)
• Experience building developer experience platforms or internal tooling