Principal Software Engineer

Toast; Ireland; On-site; EUR 140,000 - 210,000; Full time

Benefits offered by this job

Unlimited vacation

Sabbatical after five years

Professional development reimbursement

Wellness stipend

401(k) and matching

Medical, Dental, & Vision coverage

Mental Health benefits

Backup childcare support

Job summary

Toast seeks a Principal Engineer to lead AI agent architecture for the Team area within our FinTech line. You will drive scalable, secure systems while writing code and prototyping new patterns under load.

You will mentor engineers, align architectural patterns with product roadmaps, and collaborate across Toast to share best practices in agent-based development and LLM integration.

Qualifications

• 10+ years of experience designing, building, and operating highly scalable, mission-critical distributed systems and SaaS products (ideally AWS-hosted).
• Proven track record of leading complex technical initiatives and delivering robust software architecture from design to production.
• Effective communication: ability to articulate complex technical ideas clearly to both technical peers and product leadership.
• Strong enthusiasm for agentic development practices, LLM integration, and modern software paradigms.
• Balanced expertise: design high-level technical solutions on whiteboard while remaining connected to code and performance.
• Experience building systems that leverage LLMs, autonomous agents, or ML models.
• Hands-on experience with enterprise integration frameworks (e.g., Apache Camel) or event-driven messaging systems (e.g., Apache Pulsar).
• Experience establishing robust CI/CD, testing, and deployment strategies for complex systems.
• Domain knowledge in workforce management or restaurant operations.

Responsibilities

• Lead architectural design, technical execution, and implementation of AI agents for Toast’s Team area within our FinTech line.
• Serve as a key technical leader, driving modern architectural patterns and spec-driven development toward high-impact software.
• Define and execute the technical architecture for AI agents, ensuring scalable, reliable, and secure systems.
• Partner with Engineering Managers and Product Managers to translate roadmaps into robust technical designs.
• Maintain hands-on presence: write code, prototype patterns, and resolve bottlenecks under load.
• Collaborate with peers to align on best practices, agent patterns, and spec-driven development.
• Mentor and elevate engineers within the Team area, fostering technical excellence and continuous learning.

Skills

Distributed systems design

AWS / cloud

LLMs / agent-based systems

Leadership

CI/CD

Education

Bachelor's degree in Computer Science or related field

Tools

Apache Camel

Apache Pulsar

Job description

• Your mission is to lead the architectural design, technical execution, and implementation of AI agents and infrastructure for Toast’s Team area within our FinTech line of business
• The Team area is a mission-critical space on which our restaurants rely to manage their staff and optimize their labor
• As a Principal Engineer, you will serve as a key technical leader in the group, driving modern architectural patterns—including spec-driven development and agentic workflows—to deliver high-impact software
• Define and execute the technical architecture for AI agents within the Team domain, ensuring systems are scalable, reliable, and secure
• Partner closely with Engineering Managers and Product Managers to translate product roadmaps into robust technical designs and deliverables
• Maintain a strong hands-on presence, writing code, prototyping new patterns, and resolving complex technical bottlenecks under load
• Collaborate with Principal and Senior Principal Engineers across Toast to align on best practices, agent patterns, and spec-driven development paradigms
• Guide, mentor, and elevate engineers within the Team area, fostering a culture of technical excellence and continuous learning

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

10+ years of experience designing, building, and operating highly scalable, mission-critical distributed systems and SaaS products (ideally AWS-hosted)

Proven track record of leading complex technical initiatives and delivering robust software architecture from design to production

Effective communication: Ability to articulate complex technical ideas clearly to both technical peers and product leadership

Strong enthusiasm for agentic development practices, LLM integration, and modern software paradigms

Balanced expertise: Ability to design high-level technical solutions on a whiteboard while remaining deeply connected to code-level execution and system performance

Experience building systems that leverage LLMs, autonomous agents, or ML models

Hands-on experience with enterprise integration frameworks (e.g., Apache Camel) or event-driven messaging systems (e.g., Apache Pulsar)

Experience establishing robust CI/CD, testing, and deployment strategies for complex systems

Domain knowledge in workforce management or restaurant operations