Principal Engineer - Infrastructure

The salary range for this role is negotiable, the range being $200,000 - $300,000 per year.  About Sezzle: With a mission to financially empower the next generation, Sezzle is revolutionizing the shopping experience beyond payments, blending cutting-edge tech with seamless, interest-free installment plans that make shopping smarter and more accessible. We’re not just transforming payments; we’re redefining how people discover, interact with, and purchase the things they love while driving real impact on merchant sales through increased conversions and higher order values. As we continue to shape the future of fintech and retail, we’re building an innovative, dynamic team passionate about creating more than just a transaction but a truly unique shopping journey. If you’re excited about pushing boundaries in tech and delivering a game-changing experience for consumers and merchants alike, come join us at Sezzle and help create the future of shopping! Compensation: For this principal development role, with 15+ years of experience, the annual compensation range is $200,000 to $300,000. This range acknowledges the extensive expertise, leadership capabilities, and significant contributions expected at this level, offering a competitive salary to reflect the value of advanced skills and experience. About the Role:  We are seeking a talented and motivated best-in-class Principal Engineer with a focus on Infrastructure. This role presents an exciting opportunity to thrive in a dynamic, fast-paced environment within a rapidly growing team, with abundant prospects for career advancement.This is a hybrid role with a high degree of autonomy and authority to identify and resolve problems you see in our infrastructure, deployments, repositories, operational workload, and overall systems.  You should consider yourself a DOer to be a good fit for this role. We expect you to bring a deep well of experience to play, and with AI tooling, you should be a large force for scaling in the organization. Key Responsibilities Architect, upgrade, design, and build scalable infrastructure solutions leveraging Kubernetes, AWS, RDS (MySQL/Postgres), and modern distributed patterns. Help drive the infrastructure and engineering teams’ roadmaps, leading us to higher levels of reliability, recoverability, and scalability.  Find and fix issues across our systems before they become issues in production, through tooling, alerts, AI, collaboration with teams, whatever it takes. Drive capacity planning, benchmarking, and work with the team to stress test our systems, find bottlenecks, and prepare for further growth in the business. Define, maintain and enforce SLAs and alerts across our infrastructure. Help Lead Sezzle’s AI enablement efforts, identifying opportunities to apply AI and automation to enhance infrastructure reliability, developer productivity, and internal tooling. Build in consistency and scalability across a distributed microservices architecture while maintaining performance and reliability. Establish and evolve engineering best practices for observability, security, and CI/CD across teams. Mentor engineers and champion a culture of learning, innovation, and operational excellence. Collaborate cross-functionally to translate business goals into technical roadmaps and deliver results that matter. Minimum Requirements:  15+ years of professional software engineering or infrastructure engineering experience, including significant backend development and production engineering experience. Deployed significant changes to a production application or infrastructure configuration in the past 30 days. Strong proficiency in Golang, with experience building and maintaining RESTful APIs. Deep expertise with SQL-based RDBMS (MySQL, PostgreSQL) and experience optimizing schema and queries for performance at scale. Solid understanding of distributed systems design patterns (e.g., transactional outbox, event-driven architecture and stream processing, queues). Demonstrated ability to bring new ideas forward, influence decisions, and lead complex technical initiatives. Bachelor’s degree in Computer Science or equivalent practical experience. Preferred Knowledge and Skills: Familiarity with AI developer tooling like Claude Code, Gemini CLI, Codex, Cursor and using it to be a more productive engineer. Experience with AWS cloud infrastructure, mainly AWS Aurora RDS, both MySQL and Postgres. Proficiency in observability tools (Prometheus, Grafana, Datadog, New Relic). Experience with data engineering, data pipelines and data warehousing. Experience with CI/CD pipelines and deploying containerized microservices in Kubernetes. Track record of shipping commercial APIs and data-driven applications in high-growth environments. Proven leadership in guiding technical direction, improving system reliability, and scaling high-traffic services. About You:  You have relentlessly high standards - many people may think your standards are unreasonably high. You are continually raising the bar and driving those around you to deliver great results. You make sure that defects do not get sent down the line and that problems are fixed so they stay fixed. You’re not bound by convention - your success—and much of the fun—lies in developing new ways to do things You need action - speed matters in business. Many decisions and actions are reversible and do not need extensive study. We value calculated risk-taking. You earn trust - you listen attentively, speak candidly, and treat others respectfully. You have backbone; disagree, then commit - you can respectfully challenge decisions when you disagree, even when doing so is uncomfortable or exhausting. You have conviction and are tenacious. You do not compromise for the sake of social cohesion. Once a decision is determined, you commit wholly. You deliver results - you focus on the key inputs and deliver them with the right quality and in a timely fashion. Despite setbacks, you rise to the occasion and never settle. Sezzle’s Technology Stack: Languages: Golang, Typescript, Python Frontend: Typescript - React and React Native Backend: Golang Database: MySQL, Postgres, Elasticsearch DevOps & Cloud: AWS, Kubernetes Version Control: Git CI/CD: Gitlab Testing: Developer and AI-driven, focus on automated end-to-end, integration, and unit tests Open Source: Sezzle is focused on using open source, and we build what we can before buying! What Makes Working at Sezzle Awesome?  At Sezzle, we are more than just brilliant engineers, passionate data enthusiasts, out-of-the-box thinkers, and determined innovators; we are skilled musicians, yogis, cyclists, chefs, golfers, dog-lovers, and rock-climbers. We believe in surrounding ourselves with not only the best and the brightest individuals, but those that are unique and purpose-driven in all that they do. Our culture is not defined by a certain set of perks designed to give the illusion of the traditional startup culture, but rather, it is the visible example living in every employee that we hire. Perks & Benefits:  Unlimited PTO, volunteer hours and sabbatical  Life, STD/LTD, medical, dental and vision insurance  Highly discounted LifeTime gym membership 401k with match Collaborative fun co-workers The opportunity to join the fastest growing FinTech alongside a team of motivated and driven individuals CCPA Disclosure: Sezzle Inc. is committed to protecting the privacy of our job applicants. In compliance with the California Consumer Privacy Act (CCPA), we inform California residents about the personal information we may collect, the purposes for its collection, and your rights under the CCPA. For details about the categories of personal information we collect and your rights under the CCPA, please visit the California Office of the Attorney General's CCPA page. By submitting your application, you acknowledge that you have read and understood this CCPA disclosure. Equal Employment Opportunity: Sezzle Inc. is an equal opportunity employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. We do not discriminate based on race, color, religion, sex, national origin, age, disability, genetic information, pregnancy, or any other legally protected status. Sezzle recognizes and values the importance of diversity and inclusion in enriching the employment experience of its employees and in supporting our mission. #Li-remotePay Range$200,000—$300,000 USD