Principal Software Engineer

Toast; United States; On-site; USD 120,000 - 160,000; Full time

Job summary

Toast is actively seeking a Principal Software Engineer to join the AI & Strategy Engineering team. This role focuses on building innovative 0-to-1 tools to transform our sales operations, emphasizing backend engineering and machine learning implementation.

The successful candidate will work closely with senior leadership, responsible for architecting high-performance backend systems and integrating machine learning models to enhance operational efficiency. Strong expertise in backend programming and systems architecture is essential.

Qualifications

• Extensive experience in building complex, distributed backend systems.
• Hands-on experience deploying Machine Learning models in production.
• Ability to design and manage data flow across disparate systems.

Responsibilities

• Architect and code high-performance backend services and ML pipelines.
• Build and prototype new internal products from scratch.
• Design and implement ML models for real-time sales recommendations.
• Ensure seamless integration with custom quoting engine and Salesforce.

Skills

Backend languages (Java, Go, Python)

Machine Learning model deployment

Event-driven architecture design

Complex system integration

Education

Bachelor’s or Master’s degree in Computer Science

Tools

Salesforce Apex/LWC

AWS data services (SageMaker, Lambda, SQS)

Job description

About the Role

Toast is looking for a hands‑on Principal Software Engineer to join the AI & Strategy Engineering team. In this role, you will be a primary builder of 0-to-1 tools designed to revolutionize how our sales teams operate. This isn't about maintaining legacy systems; it’s about writing the code and building the intelligence models that eliminate friction across the Go-To-Market stack.

Working under a Senior technical leader, you will be responsible for the "heavy lifting" of backend engineering and Machine Learning implementation. You will bridge our custom quoting software and Salesforce with intelligent, agentic workflows that allow sales users to make faster, data-backed decisions.

Responsibilities

• Hands-on Execution: Spend the majority of your time "hands-on-keyboard," architecting and coding high-performance backend services and ML pipelines.
• 0-to-1 Development: Build and prototype new internal products from scratch that leverage LLMs and Agentic AI to automate account research, lead prioritization, and complex quoting logic.
• Core Intelligence Models: Design and implement ML models that provide real-time recommendations to sales users, reducing manual entry and increasing deal velocity.
• Infrastructure Integration: Develop the backend connective tissue between our custom quoting engine, Salesforce, and internal data lakes to ensure a seamless, low-latency end-to-end experience.
• Technical Problem Solving: Act as a domain expert to solve complex synchronization and architectural challenges across the GTM stack, ensuring systems are scalable and resilient.
• Quality & Mentorship: Drive engineering excellence through rigorous code reviews, automated testing, and by modeling best practices for SE1-SE3 engineers on the team.
• Build Great Products: Deliver significant core capabilities that have broad impact; take high-level goals and turn them into sequenced, production-ready code.
• Problem Solve: Anticipate shifts in product needs and build flexible, decoupled backend systems that can evolve with our AI strategy.
• Deliver Quality: Ensure the reliability of GTM tools by building deep observability into every service you ship.

Requirements

• Deep Backend Expertise: Extensive experience in backend languages (Java, Go, Python) with a track record of building complex, distributed systems.
• Applied AI/ML Skills: Practical, hands‑on experience deploying Machine Learning models and building with LLMs (e.g., LangChain, RAG architectures, or Model Fine-tuning) in a production environment.
• Technical Complexity: Experience building or deeply integrating with complex enterprise software, specifically custom quoting engines or CRM internals (Salesforce Apex/LWC).
• Systems Architecture: Ability to design event-driven architectures and manage data flow across disparate systems with high integrity.
• Education: Bachelor’s or Master’s degree in Computer Science, or a related technical field.

What will help you stand out (Nonessential Skills/Nice to Haves)

• Experience building internal "Sales Tech" or "Fintech" tools that directly impact revenue.
• Familiarity with AWS data services (SageMaker, Lambda, SQS).
• A passion for removing "human-in-the-loop" friction through intelligent automation.