Senior Test and Resiliency Engineer

Princeton IT Services, Inc; St. Louis (MO); On-site; USD 110,000 - 150,000; Full time

Job summary

Princeton IT Services, Inc. in St. Louis is seeking a senior engineer or test architect to define and execute validation strategies for functional behavior, transaction integrity, performance, failover, recovery, monitoring, and production readiness.

This onsite role requires 8+ years of relevant experience. You will build end-to-end test plans across lab and production-like environments, validate traffic and TCP connections during maintenance and outages, and work with developers on root-cause

Qualifications

• 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.

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.

Skills

Resiliency testing

TCP/IP troubleshooting

Automated testing

Performance tools

Defect analysis

Job description

Location : St Louis, Missouri (onsite 5 days)

Seniority

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

Location : St Louis, Missouri (onsite 5 days)

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.