Oddbean

IIR, as currently implemented, you still download and validate it. Assumeutxo just lets you get a node up and running instantly, while core does the actual validation on background. The plan though is to allow a "don't bother" option that doesn't download at all. I haven't seen any talk on this direction you mentioned though. What would be the use case for that?

In most cases I understand that the primary bottleneck to bootstrapping a node is the TX verification. IBD would happen much quicker if validation could be skipped, in favour of instantiating a specified UTXO set. If we skip downloading the blockchain data altogether, we would only be able to operate as a pruned node. Pruned nodes lack a lot of functionality, like the ability to robustly support a Lightning node, running on top. If assumeUTXO lets you get a functional node up and running, while the IBD takes place in the background, that's a good step in the right direction. If the provision of a UTXO set could in some way negate the necessity for validation, as part of the IBD, that would be even better....

Well, I think it's pretty possible to do this, I even dare to say, trivial. You'll need to build indexes like txindex, but this is relatively cheap. My curiosity was around why using ln on a pruned node isn't robust. It should make no difference, since ln node doesn't look for historical transactions, only UTXOs

If they've managed to make it work, well and good. Lightning was just one example of a limitation pruned nodes may face. Another would be trying to build something like a block explorer.. or any other application that relies on querying transaction history.