Konrad Krok
Senior Mainframe Developer | COBOL & PL/I
Salaire / Taux journalier
Varsovie, Pologne
Freelance
Expertises
Langues
À propos
Introduction
Mainframe Solutions Architect with 10+ years optimizing legacy systems for investment banking and payments. Proven expertise in modernizing high-volume trading & payment platforms, enhancing transaction processing performance, and integrating APIs while ensuring system stability. Specialized in PL/I, COBOL, Db2, and CICS—delivering scalable, compliant solutions for mission-critical financial applications.
Expérience de travail
SDC Poland
juin 2015 - Présent
11 ans 5 mois
Varsovie, Pologne
Solutions Architect
nov. 2019 - Présent
7 ans
Varsovie, Pologne
Investment and Capital Markets department - Design Scalable Mainframe Architectures – Develop high-performance mainframe solutions for investment and capital market applications using mainframe technologies. - Optimize Trading & Risk Management Systems – Enhance trade execution, settlements on mainframe platform for speed, accuracy, and compliance. - Modernize Legacy Systems – Lead mainframe modernization by integrating APIs while maintaining system stability. - Enhance High-Volume Transaction Processing – Optimize batch and real-time processing for large-scale financial transactions, ensuring high availability and minimal latency. - PL/I ( PL/1 ), COBOL, EGL, JCL, DB2, CICS, MQ, VSAM - OPC, IBM Omegamon, IBM Db2 Query Monitor, IBM Fault Analyzer, IBM APA for z/OS
Senior PL/I Developer
juin 2015 - oct. 2019
4 ans 5 mois
Varsovie, Pologne
Payments and Cards department - Develop & Maintain Payment Systems – Design, enhance, and support mission-critical payment processing applications using PL/I, COBOL, JCL, Db2, and CICS. - Ensure Transaction Accuracy & Security – Optimize and maintain secure, high-performance transaction processing for card payments, settlements, and fund transfers. - Troubleshoot & Optimize Performance – Identify bottlenecks, enhance system performance, and ensure high availability and reliability. - Ensure Compliance & Industry Standards – Implement and maintain PCI DSS and financial regulations in payment processing systems. - PL/I ( PL/1 ), COBOL, JCL, DB2, CICS, MQ, VSAM, TWS(OPC) - MS SQL, Raincode, SOAP UI
IT Consultant
CGI
nov. 2013 - mai 2015
1 an 7 mois
Varsovie, Pologne
IT Consultant – Mainframe Specialist Insurance industry Programming (designing, implementing, developer's testing) - CA Gen development (client & server) - Mainframe development (online & batch, PL/1, EasyTrieve, SQL/DB2) - Batch development (JCL, ICETOOL, IBM Utilities) Process management Incident, Major Incident and Problem manager
Batch Operations Analyst
IBM Polska Business Services
juin 2013 - oct. 2013
5 mois
Varsovie, Pologne
This role has overall responsibility for scheduling and control of batch processing in a multi vendor environment. - Control and routing as appropriate batch applications for internal and external clients. - Recovery activities in production and support of clients in critical situations. - Control the scheduling of ALL batch processing via approved batch scheduling tools. IBM Mainframe (z/OS) platform: -TWS (Tivoli Workload Scheduler), ZEKE, ZEBB (ASG) Wintel platform: -BMC Control M, Informatica Workflow Monitor - Cortex, FlexCube, Qualco
Associate Software Enginner
CA Technologies
sept. 2012 - mai 2013
9 mois
Prague, Tchéquie
Associate Software Engineer in OPS/MVS team Programming: - HLASM – High Level Assembler, Cobol - REXX, JCL, ISPF Panels Products usage: -CA OPS/MVS, CA Sysview, CA Endevor, CA Netmaster
IT Specialist
IBM
nov. 2010 - août 2012
1 an 10 mois
Wroclaw, Lower Silesian District, Poland
IT Specialist - Shift Leader of z/OS Console Operations Technical support experience: - Experience in Mainframe (zSeries) - Experience in Tivoli System Automation and Tivoli Netview for z/OS - Basic knowledge in JCL, Omegamon/RMF, HMC, JES2 - Knowledge in Ability to work in TSO, ISPF, SDSF, TWS (OPC, Control-M) - File transfers: Connect:Direct/ Spazio / Netmaster / Cross File Transfer Incident/event management experience: - Problem determination, analysis and resolution. - Change delivery including new business implementation.
Internship
eConsulting Sp. Z o. o. IT Consulting & Services
oct. 2008 - juil. 2009
10 mois
Business purpose: creation of CRM system Technologies: C#, ASP.NET 3.5, ASP.NET AJAX, Subversion, MSSQL, NHibernate, NUnit
Formation
SGH Warsaw School of Economics
Business Analyst/Analityk biznesowy – profesjonalista na styku IT i biznesu
2014 - 2015
2 ans
Rzeszow University of Technology
Mgr Inż., Computer Science
2005 - 2010
6 ans
Licences et certifications
Complete A.I. & Machine Learning, Data Science Bootcamp
Délivré le : févr. 2025
Get to know AI
Délivré le : janv. 2025
Prince2® Foundation
Délivré le : avr. 2015
ITIL® Foundation Certificate in IT Service Management
Délivré le : juin 2014