Senior Associate, Mainframe Infrastructure Testing Engineer

We are seeking an experienced Senior Associate, Mainframe Infrastructure Testing Engineer to provide specialized systems knowledge and testing coverage across IBM mainframe services. This position combines systems-level mainframe expertise with environment management engineering. The engineer will assess change impacts, define and execute validation strategies, verify platform and workload readiness, analyze failures, and provide clear evidence-based recommendations for changes affecting critical services.

The ideal candidate brings strong z/OS and mainframe ecosystem knowledge and understands that this is a testing position. The priority is deep systems expertise that can be applied to independent validation, with testing processes and DTCC-specific practices developed through onboarding and knowledge transfer.

Your Primary Responsibilities:

• Conduct planning, estimation, test design, execution, defect management, reporting, and stakeholder sign-off for mainframe infrastructure testing engagements.
• Assess application-to-mainframe dependencies and change blast radius to determine affected systems, test scope, sequencing, regression needs, and operational risk.
• Define risk-based coverage for z/OS, middleware, batch processing, scheduling, security, storage, networking, resiliency, and lower-environment readiness.
• Validate mainframe upgrades and platform changes, including z/OS, middleware, security, encryption, automation, scheduling, and modernization initiatives.
• Support Capacity Stress Testing and performance testing by evaluating workload behavior, resource utilization, system stability, bottlenecks, and test outcomes.
• Validate non-production environments, including access, connectivity, services, and batch schedules.
• Design or maintain test coverage for z/OS, Db2, CICS, IBM MQ, mainframe storage, TCP/IP/network services, and enterprise scheduling with clear, traceable test plans, test cases, results, defects, approvals, and audit evidence.
• Analyze job failures, connectivity issues, middleware errors, performance degradation, and cross-platform integration defects; coordinate troubleshooting with engineering and application teams.
• Partner with mainframe systems engineering, operations, architecture, cybersecurity, storage, network, database, scheduler, application, and change-management teams.
• Automate repeatable validation and integrate test evidence with source-control, pipeline, workflow, or reporting tools.
• Transfer specialized mainframe knowledge, mentor engineers, and reduce key-person dependency through documentation and cross-training.

• Minimum of 6 years of related mainframe systems engineering, mainframe infrastructure testing, systems programming, production support, performance engineering, or platform architecture experience; 9 or more years preferred for candidates expected to operate as the primary onshore SME.
• Hands-on or systems-level depth in IBM z/OS and several related technologies such as JCL, CICS, Db2, IBM MQ, RACF, TCP/IP, storage, or enterprise scheduling.
• Demonstrated experience assessing complex infrastructure changes, identifying dependencies and failure modes, and translating technical risk into a practical test strategy.
• Experience with capacity, stress, performance, extended-run, upgrade, migration, disaster-recovery, or production-readiness testing.
• Experience working across engineering, operations, application, cybersecurity, architecture, and change-management teams.
• Bachelor’s degree is preferred, or equivalent relevant experience.
• Financial services or other highly regulated, high-availability transaction-processing experience strongly preferred.

Technical Skills:

• Platform and architecture: IBM z/OS architecture and operating-system concepts; LPARs; Sysplex and Parallel Sysplex; workload distribution; IPL and system-startup concepts; environment health and dependency analysis.
• Transaction, database, and messaging: Working knowledge of CICS, Db2 for z/OS, and IBM MQ for z/OS, including service dependencies and validation considerations.
• Batch and scheduling: Strong JCL knowledge; JES2/JES3 concepts; batch workload analysis; job and dataset dependencies; restart and recovery; CA-7, ESP, Control-M, or comparable workload automation platforms.
• Security and access: RACF concepts, privileged and non-privileged IDs, access controls across production, DR, and test environments.
• Network and file transfer: FTP/SFTP, NDM/managed file transfer concepts and cross-platform connectivity.
• Storage and resiliency: DASD and storage concepts, backup and recovery, replication, failover, disaster recovery, business continuity, and resiliency validation.
• Testing and diagnostics: Risk-based test strategy, performance and capacity testing, extended-run testing, upgrade testing, defect analysis, expected return-code verification, logs and system messages, and evidence-based sign-off.
• Automation: Ability to use scripting or automation to improve repeatability. Experience with REXX, Python, Shell, Ansible, Jenkins, Git, or comparable tools is beneficial.

Talents Needed for Success:

• Mainframe capacity stress testing and performance analysis.
• Extended-run or endurance testing of business-critical workloads.
• ESP migration or comparable scheduler migration and validation.
• RIT Lab, DR, or lower-environment readiness and refresh validation.
• z/OS and middleware upgrade testing.
• Development of reusable mainframe test cases, validation scripts, dashboards, or evidence-collection automation
• Systems thinking and the ability to connect mainframe services, application workloads, dependencies, failure modes, and business impact.
• Strong troubleshooting and analytical skills, with disciplined attention to return codes, logs, schedules, system messages, and test evidence.
• Ability to work independently as a trusted mainframe testing SME while collaborating effectively across technology organizations.
• Clear written and verbal communication, including concise presentation of testing status, risks, defects, and recommendations to technical and leadership audiences.
• Commitment to knowledge transfer, documentation, engineering quality, resiliency, accountability, and continuous improvement.

Full time

Are you ready to make an impact at DTCC?

Do you want to work on innovative projects, collaborate with a dynamic and supportive team, and receive investment in your professional development? At DTCC, we are at the forefront of innovation in the financial markets. We’re committed to helping our employees grow and succeed. We believe that you have the skills and drive to make a real impact. We foster a thriving internal community and are committed to creating a workplace that looks like the world that we serve.

Pay and Benefits:

• Competitive compensation, including base pay and annual incentive
• Comprehensive health and life insurance and well-being benefits, based on location
• Pension / Retirement benefits
• Paid Time Off and Personal/Family Care, and other leaves of absence when needed to support your physical, financial, and emotional well-being.
• DTCC offers a flexible/hybrid model of 3 days onsite and 2 days remote (onsite Tuesdays, Wednesdays and a third day unique to each team or employee).

With over 50 years of experience, DTCC is the premier post-trade market infrastructure for the global financial services industry. From 20 locations around the world, DTCC, through its subsidiaries, automates, centralizes, and standardizes the processing of financial transactions, mitigating risk, increasing transparency, enhancing performance and driving efficiency for thousands of broker/dealers, custodian banks and asset managers. Industry owned and governed, the firm innovates purposefully, simplifying the complexities of clearing, settlement, asset servicing, transaction processing, trade reporting and data services across asset classes, bringing enhanced resilience and soundness to existing financial markets while advancing the digital asset ecosystem. In 2024, DTCC’s subsidiaries processed securities transactions valued at U.S. $3.7 quadrillion and its depository subsidiary provided custody and asset servicing for securities issues from over 150 countries and territories valued at U.S. $99 trillion. DTCC’s Global Trade Repository service, through locally registered, licensed, or approved trade repositories, processes more than 25 billion messages annually. To learn more, please visit us at www.dtcc.com or connect with us on LinkedIn, X, YouTube, Facebook and Instagram.

DTCC proudly supports Flexible Work Arrangements favoring openness and gives people freedom to do their jobs well, by encouraging diverse opinions and emphasizing teamwork. When you join our team, you’ll have an opportunity to make meaningful contributions at a company that is recognized as a thought leader in both the financial services and technology industries. A DTCC career is more than a good way to earn a living. It’s the chance to make a difference at a company that’s truly one of a kind.

Learn more about Clearance and Settlement by clicking here.

Serves as a dedicated technology resource for advancing DTCC’s business opportunities and providing industry thought leadership for leveraging new technology. The goal of this new department is to partner internally with IT, our business and regulatory divisions and externally with clients, regulators, and fintech vendors, to help build new platforms and business models to advance DTCC’s mission to support the financial markets.