[GZGavinZhao]

How is this different from Alipay/WeChat Pay in China? Handling transactions of this volume is an amazing technological feat, kudos to the team! However, I don't think this mobile QR code paying system is anything novel. Alipay rose to popularity much earlier (I can't recall exact when, but it was already super popular in ~2010, and definitely ubiquitous by 2015).

[bri3d]

It’s a completely different backend model; as far as I know alipay works just like PayPal where transactions are fully “internal” - the buyer pays Ant Group and the seller cashes out at a later date.

UPI is a real inter-organization payment system more akin to credit card processing, where fund requests flow from the payer, through a payer processor, through a merchant processor, and finally to their end destination, and the actual reconciliation happens through a bank transfer system. It’s a much less centralized system.

[zaptheimpaler]

UPI is more like a routing/reconciliation layer like VISA that can work across any bank/wallet, and that core is run by a non-profit government org. It doesn't take custody of the funds and doesn't centralize the information into a private corporation. The fee is also minimal and flat-rate with no profit incentive, instead of paying a percentage of the entire countries transaction volume to some private company. I would guess that adds up to a huge amount of money saved overall.

[repeekad]

Much of the world doesn’t like having a single entity own and control the process end to end, it’s more efficient but there’s only one point of trust. Multiple institutions that have to check each other means you don’t have to trust a single entity with everything.

[dyauspitr]

Alipay is the usual deal with a single company’s server and then they settle those later. Relatively basic compared to this.

[agnishom]

The main difference is that the core API is public infrastructure (run by a government authority). The apps are run by different companies but the backbone is interoperable by design