The multi-rail debate is over - most US banks enabling instant payments now run both RTP and FedNow. The cost moved from the strategy deck to the operations floor, where exception handling becomes a decision tree, reconciliation becomes real-time position-keeping across two liquidity models, and routing is a per-transaction decision in milliseconds.
The translator is ready, the mapping is tested, the structured fields are wired - and the project is still not on track, because the customer records are missing structured address data across KYC, core banking, and correspondent files. In November 2026, SWIFT, SEPA, and CHAPS start rejecting unstructured addresses, and most banks are framing the wrong problem.
Payment modernization projects do not stall at the architecture layer. They stall at the security review layer - threat models built for monoliths, questionnaires written for general software, cycles tuned for annual releases. The teams that ship on time put security in the room before design, not after.
Two US regulatory threads just lined up. The GENIUS Act created a federal pathway to issue payment stablecoins, and the OCC's new rule lets national trust banks hold digital assets in non-fiduciary custody - then conditionally chartered Coinbase as one. Issuance and custody can now sit inside the same federally regulated counterparty.
Payment integration usually starts with a PDF, a sandbox that takes days to provision, and a support email that answers in 48 hours - and the third email is where patience dies and a competitor gets Googled. I built a self-service workbench to close the distance between what a platform can do and what a developer can figure out alone.
Every payment system routes across multiple rails - ACH fails, traffic moves to wire, and wire is dear for small amounts so you route to RTP. Most AI systems still call one model and hope it stays up. The LLM gateway is the same routing engine payments has run for decades, and it needs the same three things to count.