10/17/2026 updated
100 % available
COBOL Mainframe (Host) Modernization | AI Code Validation | Data Migration & Reconciliation | SQL
Miami, USA
Germany
BS Computer Science, MS Computer Science Education, PhD Information SystemsAbout me
Enterprise Data Migration & Mainframe Modernization Architect (PhD). 35+ years in IT field with deep expertise in COBOL, JCL, VSAM, CA-IDMS across z/OS. Expert in data reconciliation & auditing AI tool (watsonx for Z) translations. 100% remote with occasional travel. B2B via U.S. LLC.
GitHub CopilotBusiness Rule Management SystemsBusiness AnalysisCOBOL (Programming Language)Data ValidationData CleansingData ConversionExtract Transform Load (ETL)Data MappingData TransformationData MigrationData QualityJob Control Language (JCL)IBM MainframeIdms
COBOL / IBM Mainframe (Host) – 40+ years
- COBOL, JCL, VSAM (KSDS, alternate indexes), CA-IDMS
- z/OS, MVS, OS/390 – batch and online applications
- Legacy analysis: program and file inventories, call graphs, business-rule extraction
Legacy Modernization & AI-Assisted Migration
- Reviewing and validating AI-generated analyses and code (GitHub Copilot, IBM watsonx Code Assistant for Z)
- IBM watsonx Code Assistant for Z – hands-on lab: Understand (ADDI), Refactor, Explanation, Transform (COBOL to Java), Validate; IBM badge 2026
- Equivalence / parallel-run testing: original COBOL vs. converted code
- Reading CICS/DB2 code (IBM GenApp lab)
- Currently building hands-on experience with Rocket (Micro Focus) Visual COBOL
Data Migration
- Source-to-target mapping, zoned-decimal decoding, loading into SQL
- Reconciliation: record counts, control totals, reject logs
- Legacy-to-COTS migrations in the public sector (18 years)
Other
- PhD in Information Systems; 19 years university teaching (databases, SQL, SDLC, Python)
- SQL, relational databases, data modeling; Python (working knowledge)
- Technical documentation, functional specifications, UAT
- Languages: English (business), Spanish (native), German (basic, A1–A2)
Experience
Professional experience10+ years
Freelancer since2026
Languages
GermanBasic knowledgeEnglishFluentSpanishNative speaker
Project history
Focus: End-to-end demonstration of AI-assisted modernization on a COBOL/JCL/VSAM batch program (credit-card interest calculation).
Reviewed GitHub Copilot's analysis line by line against the source: 6 of 10 AI claims required correction, including business logic the AI invented.
Migrated a VSAM account master to SQL with source-to-target mapping and full reconciliation (counts, control totals, reject log); escalated a data-quality issue affecting interest-rate assignment; found and fixed a defect in the migration loader.
Ran the original COBOL (compiled unchanged) and Copilot's Python translation side by side on the same data: the AI version failed on the first record, then produced one-cent interest differences; the test also exposed a latent defect in the original program. Classified each difference as conversion bug or business decision.
Portfolio: https://github.com/DrBautista-COBOL/cobol-ai-modernization-portfolio
Technologies: COBOL, JCL, VSAM, GnuCOBOL, GitHub Copilot, Python, SQL
Project/Focus: Online instruction in Information Systems, database management, systems analysis & design, project management, and related IT disciplines.
Key Areas: Relational databases, SQL, data modeling, database design, systems analysis, SDLC, requirements analysis, and business information systems.
Key Deliverables: Developed and delivered online courses, technical assignments, database exercises, and student projects. Translated complex technical concepts into practical business and systems applications.
1984–2001 | Systems Analyst / Programmer – IBM Mainframe (Host)
Developed and supported high-volume batch and transactional applications on IBM mainframe (MVS, OS/390, z/OS). Analyzed legacy data structures, program logic, business rules and interfaces. Built data extraction and conversion processes into relational systems, with validation and reconciliation.
Technologies: COBOL, JCL, VSAM, CA-IDMS
2001–2019 | Senior Systems Analyst / Programmer
Led technical analysis and data conversion for migrations from legacy applications to COTS/enterprise platforms: source structures, business rules, interfaces, data mappings and conversion requirements. SQL-based extraction, transformation, validation, reconciliation and exception handling. Functional specifications, test scenarios and UAT documentation. Domains: billing, financial interfaces, asset and work/service management, inventory, labor.
Technologies: SQL, stored procedures, BMC Remedy, Pinnacle