Legacy batch jobs to SQL pipelines
Moving COBOL-era batch processing toward observable, idempotent ETL while keeping the remaining mainframe work in view.
Case studyOpen ↗
Work / bca-ledger-and-data-pipelines
Ledger systems and data pipelines
General Ledger operations, ETL-style batch flows, and production discipline in a large retail bank.
data-pipelinesenterprisereliability
01 / Scope
Context and ownership.
Several years on a General Ledger team in a major Indonesian bank — journal workflows, year-end procedures, legacy COBOL-era processing, and the ETL-shaped work that keeps accounting data trustworthy at scale.
Focus
- Correctness under pressure — batch and simulation cycles where a missed edge case shows up in regulatory reporting, not in a unit test log.
- Legacy-to-maintainable — moving or improving brittle processing so the next engineer can understand and change it.
- Operational support — runbooks, internal tooling, and dashboards that help people respond when production is already noisy.
This work was less about fashionable tools than keeping accounting data correct: understanding data movement, following careful procedures, and untangling processes that had outlived several generations of developers.