Not all neobanks. I use Monzo, and they had an outage a while back. I was impressed that it barely affected their functionality.
They have a stand-in system that uses a separate codebase and separate cloud provider. They have a blog post about it here: https://monzo.com/blog/tolerating-full-cloud-outages-with-mo...
The stand-in system has a limited subset of features, i.e. no bells and whistles, but enough that you can get any actual banking done.
(Not an ad / I have no connection to Monzo, I just had some appreciation for a bank doing this properly as normally banking IT is a disaster. Plus the idea of keeping a separate codebase for almost an entire bank's functionality seems very invested.)
I have always got bad vibes from Revolut...
> I have always got bad vibes from Revolut...
I opened up a Revolut account a couple of years ago with the intention of switching my current account to it (i.e. wages going into it etc), but I got spooked after hearing that they weren't registered as a UK bank and thus subject to the various regulations and protections. I tried using Chase instead and have been happy with it so far.
Starling also has a disaster recovery system across cloud providers, although it is implemented differently to Monzo's (I used to work there on multi-cloud).
Multi-cloud is really tough, tbh. It's easier said than done, especially if you care about data consistency at all.