The Role
Citi's Technology Infrastructure team is seeking a Senior Application Security Engineer (Java) to own the end-to-end engineering lifecycle, maintenance, evaluation, and rollout of critical authentication and information security platforms. This role bridges Java development, infrastructure automation via Shell scripting and SQL, and deep domain expertise in multifactor authentication mechanisms such as MFA/2FA, OTP, Challenge/Response, and RADIUS. The engineer will certify new SafeWord product releases, stage security patches, and test MFA/RADIUS integrations as part of day-to-day work. They will collaborate closely with operational and engineering teams to certify new releases, troubleshoot complex production issues, and maintain high availability, resilience, and security across enterprise authentication services. The role also supports the team's ongoing initiatives to upgrade legacy authentication components, integrate modern multi-factor mechanisms, and migrate authentication services from VMs toward containerized, cloud-based OpenShift platforms.
Responsibilities
Maintain, enhance, and debug Java-based applications and microservices supporting authentication flows and security controls.
Evaluate new software versions, third-party libraries, and security updates for compatibility, performance, and risk impact.
Implement and configure authentication frameworks and protocols including 2FA/MFA, OTP, Challenge/Response, and RADIUS.
Certify new versions of the SafeWord authentication product prior to production rollout.
Stage and validate security patches across authentication infrastructure.
Test MFA and RADIUS integrations to confirm functionality and compatibility across enterprise applications.
Build and maintain automation scripts in Shell (Bash) to streamline operational tasks and deployments.
Write and optimize database scripts and procedures using SQL and PL-SQL.
Partner with operational teams to test, validate, and certify new software releases before deployment.
Support the migration of authentication services from virtual machines toward containerized platforms on cloud ECS OpenShift.
Support the integration of modern multi-factor authentication mechanisms across enterprise applications as part of the team's legacy upgrade initiatives.
Develop and maintain Standard Operating Procedures (SOPs) for authentication platform operations.
Qualifications
4+ years' progressive experience in software engineering, application security, and/or infrastructure engineering with a strong focus on authentication systems within that experience.
Strong hands-on experience in Java programming, debugging, and maintaining enterprise Java applications.
Solid understanding of authentication mechanisms including Two-Factor/Multi-Factor Authentication (2FA/MFA), One-Time Passwords (OTP), and Challenge/Response architectures.
Practical knowledge of network authentication protocols including RADIUS, LDAP/Active Directory, Kerberos, SAML, and PAM.
Advanced proficiency in Linux/Unix operating systems, including system administration, process management, file permissions, and performance tuning.
Strong Shell scripting skills in Bash and KornShell for task automation and system orchestration.
Proficiency in writing SQL and PL-SQL queries and scripts.
Strong fundamentals in TCP/IP, DNS, SSL/TLS certificates, load balancing, and firewall rule configurations.
Hands-on experience with Splunk, including search syntax, alerts, and dashboards.
Hands-on experience with AppDynamics, including APM and transaction tracing.
Working knowledge of cloud concepts, including AWS, GCP, or enterprise private clouds.
Proven ability to collaborate cross-functionally with operations, security operations, and engineering teams.
Clear written and verbal communication skills for technical documentation and incident retrospectives.
Strong attention to security best practices, access governance, and audit readiness.
Familiarity with containerization and orchestration technologies such as Docker, OpenShift, or Kubernetes is preferred.
Experience within Financial Services, Banking, or other highly regulated enterprise environments is preferred.
Education
Bachelor's degree in Computer Science, Information Technology, Cybersecurity, Software Engineering, or a related technical field.
Industry certifications in Information Security or Networking are preferred, such as CompTIA Security+, Network+, CEH, or CCNA.
This job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.
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Job Family Group
Technology
Job Family
Systems & Engineering
Time Type
Full time
Primary Location
Irving Texas United States
Primary Location Full Time Salary Range
$125,760.00 - $188,640.00
In addition to salary, Citi’s offerings may also include, for eligible employees, discretionary and formulaic incentive and retention awards. Citi offers competitive employee benefits, including: medical, dental & vision coverage; 401(k); life, accident, and disability insurance; and wellness programs. Citi also offers paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays. For additional information regarding Citi employee benefits, please visit citibenefits.com. Available offerings may vary by jurisdiction, job level, and date of hire.
- Most Relevant Skills
- Please see the requirements listed above.
- Other Relevant Skills
- For complementary skills, please see above and/or contact the recruiter.
Anticipated Posting Close Date
Oct 28, 2026
Automated Processing and AI
We use automated processing, including artificial intelligence, for our legitimate business interests (or our reasonable and appropriate business purposes) to identify and align the candidate's skills and abilities with a specific job opening. Additionally, if you so choose, or consent, we can match your skills and abilities to other suitable roles at Citi.
Importantly, all our hiring processes and decisions, including determining your suitability for a role, are conducted, checked, and decided by individuals. Our automated processing and AI do not involve relying on automatic or autonomous decision-making. Please refer to any Jurisdictional Considerations, with specific provisions for your country (where relevant) for further details.
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