Sr IT Security Engineer

Powering the world's payments ecosystem

ACI powers the payments ecosystem - globally, and you power ACI.

You'll innovate, collaborate, and grow - in an energetic technology culture with decades of proven success.

ACIers - in all roles and levels - are truly your colleagues and many are your friends.

Our size and reach allow you to see the global impact of your work.

You are visible, your talents are valued, and you are empowered to shape the future of payments.

As a Sr.

Security Engineer in Norcross, GA, you will join a diverse, passionate team, dedicated to powering the world's payments ecosystem!

Job Purpose

The Sr.

Security Engineer is responsible for designing, implementing, hardening, and supporting enterprise security capabilities that protect company systems, platforms, and information assets.

This role blends hands-on security engineering with operational execution across cloud security, security operations, incident support, and AI security use cases.

The position partners with engineering, cloud platform, application, data/AI, and operations teams to reduce risk, improve detection and response outcomes, and support audit and control expectations.

As a senior-level role, this position also contributes technical leadership through documentation, standardization, mentoring, and continuous improvement.

Essential Functions and Responsibilities


* Design, implement, and continuously improve secure configurations and guardrails across enterprise and cloud environments, including identity and access controls, network protections, encryption, secrets management, logging, and platform hardening.


* Engineer, administer, and support enterprise security technologies spanning endpoint security, vulnerability management, SIEM/logging, identity management, monitoring, detection, and cryptographic controls.


* Drive remediation of security findings by prioritizing critical and high-risk issues, validating corrective actions, and improving repeatable control patterns.


* Build, operate, and enhance security operations capabilities, including detection engineering, SIEM/SOAR workflows, alert triage, investigation support, incident response playbooks, and operational runbooks.


* Conduct or support incident investigations, root-cause analysis, containment and eradication activities, and lessons-learned follow-through.


* Participate in the on-call support rotation for security incidents, provide technical support during active investigations and response activities, and contribute to post-incident remediation and continuous improvement.


* Develop and maintain technical documentation, engineering standards, implementation procedures, and evidence-quality artifacts to support operational consistency and audit readiness.


* Partner with engineering, cloud, application, and AI/ML stakeholders to implement scalable security controls and secure-by-default patterns.


* Perform technical assessments and proof-of-conce...