Most payment integrations still look like 2015 - custom code per platform, months-long builds. The Model Context Protocol turns MxN integrations into M+N, and payment platforms are starting to ship it. The promise is real; so are the enterprise security gaps.
Teams treat cloud like a faster data center instead of a different computing model. Banking workloads are not web apps - and lift-and-shifting a mainframe to the cloud buys you cloud costs with mainframe complexity.
Instant rails stripped out the friction that quietly prevented massive losses - and authorized push payment fraud walked straight through the gap. Once the money hits the rail it is gone, and multi-factor authentication cannot help when the victim authorizes the payment themselves.
The BIS just blueprinted a tokenized unified ledger and JPMorgan put a deposit token on a public chain - in the same week. The hard part for banks was never the blockchain. It is retrofitting core banking to carry programmable money without a big-bang migration.
Fiserv, Bottomline, and a core banking system each work fine alone. Wiring them into one payment chain is where projects go to die - and the difference between the ones that survive and the ones that become expensive lessons is a handful of boring resilience patterns.
RTP cleared $246 billion in 2024 and the headlines said instant payments had arrived. The average transaction sizes tell a quieter story - this is high-value institutional money on a faster rail, not the consumer revolution that was promised.