Senior Resiliency Test Engineer

Job TItle: Senior Resiliency Test Engineer
Location: St. Louis, MO
Job Type: Full time / Contract

Seniority: Senior engineer or test architect, ordinarily 8 or more years of relevant experience.

Mission: Define and execute the validation strategy for functional behavior, transaction integrity, performance, failover, recovery, monitoring, and production readiness.

Core responsibilities

·       Build end-to-end test plans across representative lab and lower environments.

·       Validate traffic movement and persistent TCP connections during planned maintenance and failure scenarios.

·       Verify there is no unacceptable message loss, duplication, ordering issue, or customer-visible interruption.

·       Execute functional, integration, regression, negative, failover, recovery, load, soak, and capacity testing.

·       Validate proxy bypass and return-to-legacy recovery procedures.

·       Reproduce defects, analyze logs and packet captures, and partner with developers on root-cause analysis.

·       Define test evidence, acceptance criteria, certification results, and operational sign-off inputs.

Required skills

·       Resiliency, performance, network, and integration testing.

·       TCP/IP and packet-level troubleshooting.

·       Automated test frameworks and failure-injection techniques.

·       Performance and capacity tools for high-throughput services.

·       Strong defect analysis and technical documentation.

Preferred experience

·       Financial messaging, ISO 8583, payment switching, telecom, or other high-availability transaction platforms.

·       Proxy, load-balancer, network-service, or active-active failover testing.