Salary
$5,000 – $9,500 per month (Gross USD)

About the Role
We are seeking a hands‑on, high‑impact Senior Security Infrastructure Engineer to help strengthen Sezzle’s security posture across cloud infrastructure, applications, and developer workflows. This role is adecuado for someone who thrives in a fast‑paced environment and wants to work on real‑world security problems at scale.

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.

What You’ll Do

Lead and operate vulnerability management across infrastructure, platforms, and applications – including internal scans, dependency analysis, and external findings, validating true positives and driving remediation with engineering teams

Build, operate, and mature SIEM/XDR capabilities, including log ingestion, detection rule development, alert tuning, and investigation workflows

Investigate and respond to security incidents across cloud infrastructure and applications, performing root cause analysis and driving long‑term fixes

Design and implement detection strategies for suspicious activity, including data exfiltration patterns using application and database telemetry

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

What We Look For

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

Preferred Knowledge and Skills

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

Ability to assess application and infrastructure risk and translate findings into actionable improvements

Experience aligning technical security work with regulatory and compliance expectations

Experience using automation and AI to reduce manual effort and improve consistency at scale

About You

You think proactively about securityand work to address risk early through clear design feedback and practical engineering solutions

You bring strong cloud and infrastructure judgment, especially in AWS and Kubernetes environments

You raise the bar on hardening and operational discipline, especially in CI/CD and supply chain security practices

You approach security monitoring with an investigator’s mindset and can turn telemetry into meaningful detection and response outcomes

You are excited to use automation and emerging technologies (including AI) to automate repetitive security work and improve team effectiveness

You balance strong security standards with business needs and can support privacy and compliance requirements in a practical, scalable way

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.

Languages: Golang, Typescript, Python

Frontend: Typescript – React and React Native

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!

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📌 Senior Security Infrastructure Engineer (Nezahualcóyotl)
🏢 Sezzle
📍 Nezahualcóyotl