CICS Interview Questions and Answers – 2025

CICS (Customer Information Control System) professionals are crucial in managing transaction processing systems on IBM mainframes. This guide offers 20 thoughtfully curated interview questions, categorized across behavioral, situational, technical, and cultural fit topics. Each answer is tailored to reflect practical insight, professionalism, and the latest industry expectations for 2025.

Behavioral Questions

1. Describe a time you handled a CICS region abend.
I once traced a region crash to a runaway transaction using CEMT and resolved it by purging the task and applying a fixpack recommended by IBM.
2. How have you managed performance tuning in the past?
I reviewed resource consumption metrics and optimized VSAM file usage and transaction priority levels for better throughput.
3. Share an instance when you collaborated across departments for CICS upgrades.
I coordinated with DBAs and network teams to test CICS TS upgrades in staging, ensuring compatibility with all connected subsystems.
4. Tell me about a challenging CICS-related bug you fixed.
I resolved a pseudo-conversational transaction loop by identifying improper terminal control flow and rewriting the EIBRESP logic.
5. How do you stay current with CICS best practices?
I regularly follow IBM Redbooks, attend webinars, and subscribe to the CICS DevCenter blog.

Situational Questions

6. What would you do if a CICS region failed during peak business hours?
I would prioritize bringing up the backup region, analyze logs using CICS trace, and follow up with the operations team.
7. How would you respond to a user reporting a transaction timeout?
I’d check system logs, CSMT dumps, and analyze transaction timeouts using statistics gathered via CEDA.
8. What would you do if a new program failed to link properly in CICS?
I would validate the program definition in CSD and ensure proper load module placement in the DFHRPL concatenation.
9. How would you approach a DB2-CICS connection failure?
I would review RCT entries and DSNR log errors, ensuring the DB2 attachment facility is active and compatible.
10. How would you handle a critical transaction consuming excessive CPU?
I'd identify it using performance monitoring tools like CICS SMF and rework the code to include better COMMAREA management.

Technical Questions

11. What is the role of a TCT in CICS?
Terminal Control Table maps terminal identifiers to CICS and helps manage sessions and devices during transaction processing.
12. Explain the significance of pseudo-conversational programming.
It enables better resource utilization by freeing up resources between program waits while maintaining state through COMMAREA.
13. What are some key CICS commands for resource management?
CEMT, CEDA, and CECI are the primary commands used to define, inspect, and manage resources in real time.
14. How is exception handling done in CICS?
Using EIBRESP and EIBRCODE in programs, exceptions are caught and actions taken based on the response codes.
15. How do you ensure data integrity in a CICS-DB2 environment?
By enabling syncpoints and controlling transaction commits and rollbacks using EXEC CICS SYNCPOINT.

Cultural Fit Questions

16. How do you handle high-pressure production issues?
I stay calm, isolate the root cause systematically, and ensure timely communication with stakeholders while resolving the issue.
17. How do you contribute to team success?
I share knowledge, document fixes, mentor juniors, and ensure clear communication within cross-functional teams.
18. Why do you want to work with our organization?
Your reputation in mainframe modernization aligns with my goal of contributing to cutting-edge legacy system transformations.
19. What values do you bring to this role?
Integrity, accountability, and a continuous learning mindset, especially in evolving enterprise technologies.
20. How do you ensure quality in your CICS-related work?
I implement thorough testing, code reviews, and adhere to industry standards and internal process documentation.