Montora

Montora migrates COBOL and mainframe applications to modern languages like Java, recovering the business rules buried in old code and moving one reviewed piece at a time. Crucially, it replays recorded production runs against both old and new code and compares results field by field before any change is accepted.

Banks and other institutions still run critical systems on COBOL, yet the people who understand that code are retiring and regulators increasingly want provable, auditable change. Montora's bet is that modernisation only moves forward when every migration can be verified rather than trusted on faith.

Montora Ltd was incorporated in England and Wales in 2026 to tackle a problem most teams avoid: proving that migrated legacy code still behaves exactly as the original. The company frames its approach around behavioural verification rather than a lift-and-shift rewrite.

Founder Tanveer Singh has built the platform around an auditable architecture — sandboxed isolation with no network egress, read-only filesystem, dropped privileges, and verification runs sealed with a cryptographic signature and reproduction key. It is a design clearly aimed at the compliance bar that banks running sensitive legacy systems actually demand.