Senior Security Infrastructure Engineer

📋 Job Overview

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!

🏢 About Sezzle

Sezzle is a fintech company that offers interest-free installment plans to make shopping more accessible. 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.

🎯 The Role

As a Senior Security Infrastructure Engineer, you will have a high degree of ownership and autonomy to identify risks, investigate issues, and drive meaningful security improvements across our systems. You will work across vulnerability management, detection engineering, supply chain security, and incident response - partnering closely with engineering teams to ensure security is practical, effective, and embedded into how we build and operate systems. You should consider yourself a DOer - someone who is comfortable diving into logs, analyzing systems, validating findings, and working end-to-end to get issues resolved. We value engineers who bring strong technical depth, good judgment, and the ability to turn security insights into actionable outcomes.

This role offers the opportunity to shape and scale security capabilities, including detection systems, supply chain risk controls, and security automation. With the support of modern tooling (including AI where appropriate), you will play a key role in improving efficiency, visibility, and resilience across the organization. This role combines hands-on security operations with exploratory and design work. You will spend significant time investigating and resolving real-world issues, while also researching, evaluating, and building new security capabilities across areas like detection, supply chain security, and data protection.

✅ Key Responsibilities

• Build, operate, and mature SIEM/XDR capabilities, including log ingestion, detection rule development, alert tuning, and investigation workflows
• Lead and contribute to threat modeling exercises and security design reviews to identify risks early and strengthen architecture
• Apply deep expertise in AWS and Kubernetes to design, secure, and improve resilient and secure cloud infrastructure at scale
• Drive infrastructure and CI/CD hardening initiatives, with a focus on reducing software and container supply chain risk
• Lead efforts to implement and improve dependency and container supply chain risk detection systems and controls
• Partner closely with engineering teams to remediate vulnerabilities and improve secure development and deployment practices
• Support and implement security controls aligned with PCI DSS, SOC 2, and other compliance requirements
• Develop and implement automation (including AI where appropriate) to improve efficiency in security operations, detection, and response
• Triage and validate external security findings, distinguishing true positives and coordinating remediation

📌 Required Qualifications

• 6+ years of experience in security, software, or infrastructure engineering, with hands-on experience securing cloud-based production systems and working with real-world security challenges
• Experience contributing to threat modeling and security design reviews for modern systems
• Strong hands-on experience in vulnerability management, including scanning, triage, validation, remediation coordination, and verification
• Experience working with SIEM platforms (e.g., Wazuh, Splunk, ELK) for detection engineering, monitoring, and incident response
• Practical experience triaging findings from vulnerability scanners and bug bounty programs
• Strong knowledge of AWS, Linux, and Kubernetes infrastructure, including security architecture, hardening, and operational best practices
• Experience improving infrastructure security, including CI/CD hardening and mitigating software supply chain risks
• Experience with container and dependency security tools (e.g., Snyk, Trivy, Grype, etc.)
• Ability to investigate issues directly using logs, cloud tooling, and system-level data
• Knowledge of common security vulnerabilities and mitigation strategies (OWASP, SANS, etc.)
• Working knowledge of compliance frameworks such as PCI DSS and SOC 2
• Demonstrated experience working with Claude or equivalent large language model tools is required; candidates must be comfortable leveraging AI to enhance productivity, research, and communication.

⭐ Desirable Experience

• Experience designing and tuning detection rules, reducing alert noise, and improving investigation workflows
• Strong understanding of cloud-native security controls, including IAM, network segmentation, and container security
• Familiarity with log-based detection, telemetry pipelines, and security analytics use cases
• Experience designing secure CI/CD workflows that reduce exposure to vulnerable dependencies and untrusted artifacts
• Experience aligning technical security work with regulatory and compliance expectations
• Experience using automation and AI to reduce manual effort and improve consistency at scale

🎁 Benefits

The salary range for this role is $5,000 - $9,500 per month (Gross in USD). For this principal development role, with 6+ years of experience, the compensation range is $5,000 - $9,500 USD based on experience level per month and in gross amount. 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.

🛂 Visa & Eligibility

Sezzle is an equal opportunity employer and is committed to creating a workforce that reflects the diversity of our communities. We celebrate differences and are proud to be an inclusive company where everyone can be their authentic self. We do not discriminate on the basis of race, color, religion, gender, gender identity or expression, sexual orientation, national origin, ancestry, age, marital status, pregnancy or pregnancy-related condition, genetic information, disability, veteran status or any other characteristic protected by law. Sezzle is proud to be an Affirmative Action and Equal Opportunity Employer.