ledgersformal-methodsfintech
Formal Methods for Ledger Cutovers
Dual-write, consensus checkpoints, and why mathematical invariants precede migration day.
menu_book6 min readSep 16, 2026
Why cutovers fail
Most migrations fail from unstated invariantsânot from missing tooling.
Model first
We encode settlement and reconciliation rules in TLA+ before writing dual-write adapters.
Operational proof
Every phase has a measured rollback path and continuous audit trails.