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# Sr. Systems Engineer - Mainframe API Services

- **Company:** U.S. Bank, National Association
- **Location:** Earth City, MO, United States
- **Experience:** Expert
- **Salary:** $105,400.0 - $124,000.0
- **Contract:** Permanent contract
- **Skills:** Systems Engineering, Mainframes, Web Services
- **Published:** October 28, 2026
- **Apply:** https://www.indeed.com/viewjob?jk=aa4bc55ac9304943

## About the Role

* Bachelor's degree, or equivalent work experience
 * At least 5 years of experience within a total information technology (IT) environment
 * At least 10 years of experience with the design, development and support of technology

Preferred Skills & Experience

 * Extensive experience with IBM z/OS and mainframe infrastructure.
 * Hands-on expertise with IBM z/OS Connect, Liberty, and USS.
 * Strong knowledge of REST APIs, JSON, HTTP/HTTPS, CICS, TCP/IP, DNS, and TLS/SSL.
 * Experience with RACF/SAF, key rings, digital certificates, authentication, and authorization.
 * Experience with SMF, system logs, API monitoring, performance analysis, and troubleshooting.
 * Familiarity with Datadog or similar monitoring and observability tools.
 * Experience with Jenkins, Git, Python, Groovy/Java, REXX, shell scripting, and DevOps automation.
 * Working knowledge of JCL, SDSF, z/OS Sysplex, system operations, and high-availability environments.