
The average COBOL programmer is over 55. The systems they maintain process $3 trillion a day. When that person leaves, the knowledge of why this field is COMP-3 and not COMP goes with them. IBM Bob can modernise the code. But a change that passes every static check can still produce a different result when a field hits 9,999,999.99 under real transaction volumes. Nobody catches that. Refinery does. Refinery compiles both programs using GnuCOBOL, derives boundary test values from each field's PIC declaration, zero, minimum, maximum, overflow, injects them at runtime, executes both binaries, and compares output. When a divergence is found, a per-field isolation pass reruns with each field individually to pinpoint exactly which data boundary triggered it. This is the check that catches arithmetic drift no static analyser sees. The control flow engine tracks not just which paragraphs are called, but whether they're conditional or unconditional. If Bob wraps a previously unconditional PERFORM inside an IF block, Refinery flags it HIGH, a subtle change that alters when critical business logic executes. When a change is flagged, Refinery corrects it. It retrieves the failure pattern from your estate's compliance knowledge base, sends Bob a targeted prompt, and re-runs the engine. Most failures resolve in one round. Before the audit, Refinery maps the blast radius via MCP, every CALL, COPY, REDEFINES, JCL EXEC, and VSAM reference scored 0–100. Above 50, CRO sign-off is mandatory. The governance portal gives risk officers a live feed of every audit and sign-off. Built-in chat: the CRO asks Bob in plain English, Bob answers from the audit data. Every rejection feeds the RAG knowledge base, Bob stops repeating the same mistakes on your estate. Under DORA Article 16 and SOX Section 404, regulated institutions cannot promote AI-generated code without a signed, auditable record. Refinery produces one. That's the condition under which a bank can use Bob in production.
17 May 2026