COBOL developer and mainframe specialist

I am a COBOL developer and mainframe specialist — I keep the systems running that people usually don't think about until a payment hangs or a policy renewal fails. For over fifteen years, I've worked inside the processing cores of banks and insurance companies, reading and writing COBOL that's dozens of years old and still moves real money every night. My workday consists of batch windows, decks of JCL and DB2 tables, figuring out why the night job crashed with an obscure abend code, and making sure the balances match before the branches open in the morning. I treat these systems with respect, not contempt: they are enormous, precise, and survived precisely because someone kept them in order.

I offer calm and careful work with code that has no right to break. I navigate undocumented programs, recover logic in plain language for your team, and fix defects without disturbing twenty other jobs that depend on them. When the system is ready to move forward, I plan migration properly: breaking monolithic programs into services, mapping fixed-format records to modern schemas, and running old and new paths in parallel until the numbers match down to the kopeck. I've led transitions from COBOL to Java and to the cloud, where one missed edge case would mean a call from the regulator, so I verify everything and take nothing on faith.

If you're missing a mainframe specialist, the people who wrote your core are retiring, or you simply need someone who will read a forty-year-old copybook without flinching — I'll get involved. I document as I go, explain decisions to non-technical clients, and leave the platform more resilient than it was.

— COBOL maintenance, bug fixes and enhancements on IBM z/OS
— JCL, batch scheduling and abend analysis
— DB2, VSAM and online CICS transactions
— Legacy documentation and reverse engineering of undocumented programs
— Planning and executing migrations from COBOL to Java and the cloud
— Parallel runs and reconciliation for loss-free transitions