Principal Software Engineer - Payments, Fraud & Risk

About Toast Toast is the leading restaurant platform, powering payments, financial services, and operational tools for restaurants globally. Our systems process billions of dollars annually, and our Fraud & Risk platforms are critical to protecting merchants, guests, and Toast itself. At Toast, Principal Engineers (P5) are senior technical leaders who define direction, unblock teams, and deliver scalable outcomes across the organization. Are you bready to design systems that protect revenue, stop fraud in real time, and scale globally? Role As a Principal Software Engineer (P5) on the Fraud & Risk platform, you will be responsible for end-to-end technical ownership of highly complex, business-critical systems. You Will: Define architecture and long-term technical strategy Drive execution across multiple teams Make high-stakes technical decisions with broad business impact Act as a multiplier for engineering quality and velocity You will operate comfortably in ambiguity and help Toast scale safely as transaction volumes, fraud sophistication, and regulatory complexity grow. What You’ll Do 1. Technical Direction & Architecture (Primary Accountability) Own and evolve the architecture for Fraud and Risk systems spanning multiple teams Define long-term technical vision and roadmaps aligned with Toast’s business goals Lead and approve architecture and design reviews for high-impact initiatives Make trade-off decisions across latency, accuracy, cost, scalability, and reliability 2. Fraud & Risk Systems at Scale Design and operate systems for: Real-time fraud detection and prevention Risk scoring and decisioning engines Chargeback prevention and dispute workflows Build low-latency, high-throughput distributed systems processing millions of transactions per day Partner with the Data Science team to productionize fraud and risk models with strict SLAs 3. Execution Through Influence (Not Ownership Alone) Drive complex initiatives that require coordination across multiple engineering teams Influence technical decisions without direct authority Identify systemic issues and proactively drive cross-org solutions 4. Reliability, Scale & Operational Excellence Ensure systems meet availability, durability, and compliance requirements (PCI, SOC, etc.) Design for failure modes, graceful degradation, and recovery Improve observability, incident response, and operational maturity Optimize infrastructure and architecture for cost at scale 5. Mentorship & Raising the Engineering Bar Mentor Senior and Staff engineers, helping them grow technical leadership skills Set standards for code quality, design rigor, testing, and operational readiness Lead by example with hands-on contributions where impact is highest What We’re Looking For Experience & Scope 12+ years of software engineering experience with demonstrated P5-level or equivalent impact Proven ownership of large, mission-critical systems with significant business impact History of driving results in ambiguous, fast-moving environments Fraud, Risk & Payments Expertise Deep experience in payments, fraud detection, risk systems, or financial platforms Strong understanding of real-time decisioning systems Experience working with fraud signals, rules engines, or ML-driven risk models is highly valued Technical Depth Expertise in Java or Kotlin (backend focus) Strong fundamentals in distributed systems, microservices, and event-driven architectures Deep experience with AWS and cloud-native design Strong knowledge of data stores (Postgres, DynamoDB, etc.) and messaging systems Leadership & Judgment Exceptional problem-solving and decision-making skills Strong written and verbal communication skills; able to clearly articulate complex trade-offs Comfortable being accountable for decisions with a large blast radius Our Spread of Total Rewards Toast offers a competitive compensation and benefits package that supports a healthy lifestyle and flexibility for our employees’ needs. Learn more about our benefits: Toast Benefits. Our Tech Stack Toast’s stack includes: Backend: Microservices architecture in Java and Dropwizard, AWS services (S3, RDS, Lambda), .NET/C#, and Java Frontend: React, ES6, MVC, and Angular Data: Postgres databases, RabbitMQ clusters, Apache Spark, SQS, SNS, DynamoDB, Redshift, OpenSearch, and Druid We Are Toasters Diversity, Equity, and Inclusion (DEI) are baked into our recipe for success. Toast embraces the diversity of the restaurant industry, fostering inclusivity, respect, and trust. We believe equitable opportunities and authentic principles drive success, enabling us to lead in our industry. 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. 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: https://careers.toasttab.com/locations-toast. 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 candidateaccommodations@toasttab.com. ------ 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.